Great Britain took Hong Kong from China after winning the First Opium War and took southern Kowloon after winning the Second Opium War. Portugal claimed the Macau region and kept it until 1999. France took over the region that is now northern Vietnam from China by winning the Sino-French War.
Most of the Western imperialism in China happened through forcing trade rights rather than through land grabs. After losing both Opium Wars, China was forced to open more ports for trading. China and the Netherlands traded the region that is now Taiwan back and forth over the centuries. China was also forced to give up control of Korea to Japan.