Huqin (胡琴; pinyin: húqín) are a family of bowed string instruments used in Chinese music. They consist of a round, hexagonal, or octagonal sound box at the bottom with a stick attached that protrudes upwards. Instruments in the huqin family have two strings (except the sihu, which has four strings tuned in pairs) and their soundboxes are typically covered with either snakeskin or thin wood. Huqin instruments have either two (or, more rarely, four) tuning pegs, one peg for each string. The pegs are attached horizontally through holes drilled in the stick. Most huqin have the bow hair pass in between the strings.
The most common huqin are the erhu (essentially a Chinese violin), zhonghu (Chinese viola), and gaohu (a higher pitched instrument commonly used in Cantonese music.) Over thirty types of huqin instruments have been documented.
In the 20th century, large bass huqin such as the dihu, gehu, and diyingehu were developed for use in modern Chinese orchestras. Of these, the gehu and diyingehu are essentially versions of cellos and double basses designed to have a timbre that would blend in with the sound of traditional huqin. These instruments generally have four strings and fingerboards, and are played in a similar manner to cellos and double basses, and are very different from the traditional huqin.