Such western style theater (called "huàjù" in Chinese; 話劇 / 话剧) made inroads in China under the influence of noted intellectuals such as Chen Duxiu and Hu Shih, who were proponents of a wider cultural renewal campaign of the era, marked by anti-imperialism, and a re-evaluation of Chinese cultural institutions, such as Confucianism. The enterprise crystallized in 1919, in the so-called May Fourth Movement.
Between 1920 and 1924, Cao Yu attended a Nankai secondary school, which offered a western style study program. The school maintained a society of dramatic arts in which the students were able to produce various western works, notably those of Henrik Ibsen and Eugene O'Neill, who were well-known authors in China thanks to translations published by Hu Shih. Cao Yu took acting roles in a number of the society's dramatic productions, even going so far as to assume the female role of Nora in Ibsen's A Doll's House. He is also known to have assisted in the translation of Englishman, John Galsworthy's 1909 work, Strife.
After finishing his studies at Nankai secondary school, Cao Yu was first matriculated at Nankai University's Department of Political Science but transferred the next year to Tsinghua University, where he would study until graduating in 1934 with a degree in Western Languages and Literature. During his university studies, Cao Yu improved his abilities in both Russian and English. His course of studies required reading the works of such western authors as Bernard Shaw and Eugene O'Neill, and of Russian authors such as Anton Chekhov and Maxim Gorky, as well as translated works of classic Greek writers, Euripides and Aeschylus. This immersion in western literature would mark Yu's style in all writing genres including the "spoken theater" (as opposed to sung Chinese opera), which had had little tradition in China prior to Yu's influence. During the course of his last year at the university, Cao Yu completed his first work, Thunderstorm, which would mark a milestone in Chinese theater of the 20th century.
While works of Chinese playwrights previous to Cao Yu are of fundamentally historical interest and were famed in China, they garnered little critical success or popularity on the international stage. By contrast, the works of Cao Yu were marked by a whirlwind of worldwide interest, turning Cao Yu into the first Chinese playwright of international renown.
The plot of Thunderstorm centers on one family's psychological and physical destruction as a result of incest, as perpetrated at the hands of its morally depraved and corrupt patriarch, Zhou Puyuan. Although it is undisputed that the prodigious reputation achieved by Thunderstorm was due in large part to its scandalous public airing of the topic of incest, and many people have pointed out not inconsiderable technical imperfections in its structure, Thunderstorm is nevertheless considered to be a milestone in China's modern theatrical ascendancy. Even those who have questioned the literary prowess of Cao Yu, for instance, the noted critic C. T. Hsia, admit that the popularization and consolidation of China's theatrical genre is fundamentally owed to the first works of Cao Yu.
In Cao Yu's second play, Sunrise, published in 1936, he continues his thematic treatment respecting individuals' progressive moral degradation in the face of a hostile society. In it, the history of several Shanghai women are narrated, and whose stories show their lives disintegrating in response to lack of affection and of acknowledgment by the society surrounding them, leading them down a tragic path from which they cannot escape. In 1937, Cao Yu's third play, The Wilderness (the Chinese name of which can also be translated as The Field), was released but which enjoyed less success than his previous works. The Wilderness, which was influenced by O'Neill's expressionist works, relates a succession of murders and stories of revenge set in a forest. At the time the play was published, social realism was the rage in China, and critics were not pleased with the work's supernatural and fantastical elements. There was a resurgence of interest in The Wilderness in 1980, however, and Cao Yu, then 70-years-old, collaborated in staging a production of his play. The play was made into a movie in 1987.
In 1940, Cao Yu completed the writing of his fifth play, Peking Man, considered his most profound and successful work. Set in Peking (today Beijing) as its name implies, and in the then present, surprisingly the work does not allude to the war with Japan at all, but chronicles the history of a well-heeled family that is incapable of surviving and adapting to social changes which are destroying the traditional world and culture in which they live. The title of the work is an allusion to the so-called Peking Man, the proto-human who inhabited the north of China several hundred thousand years ago. Cao Yu's recurrent themes are present, emphasizing the inability of traditional families to adapt themselves to modern society and its customs and ways.
In 1941, while still in Chongqing, Cao Yu completed a theatrical adaptation of the famous work, The Family, by novelist, Ba Jin. His last written work during the Japanese occupation was The Bridge, published in 1945 but not produced as a play until 1947, after the end of the war when Japanese troops in China formally surrendered on September 9, 1945.
During his tenure in Chongqing, Cao Yu taught classes in the city's School of Dramatic Art and completed a translation into Chinese of William Shakespeare's Romeo and Juliet.
In addition to supervising successive production of his earliest plays, Cao Yu kept on writing, and in 1956, published Bright Skies. Thereafter, in 1961, the decade of his major public recognition, he published Courage and the Sword, his first historical drama. This work, although set at the end of the Zhou Dynasty during the Warring States Period, contains pronounced allusions to the defeat of Mao Zedong's political ideology clothed in his Great Leap Forward. His and others' critiques of Mao, and the struggle for power in the halls of government, ultimately ended in the Cultural Revolution; a campaign enforced by Mao to reaffirm his power and to fight against the bourgeois and capitalist elements surfacing in both the political and cultural spheres. The attacks against intellectuals during the Cultural Revolution affected Cao Yu, causing him distress and alienation. However, he was able to rehabilitate himself after Mao's death and Deng Xiaoping subsequent rise to power as de facto ruler of China.
Cao Yu's last work was Wang Zhaojun, released in 1979. On December 13, 1996, at 86 years of age, Cao Yu died in Beijing.