中原大戦
China purchased the 42 export versions of O2U-1 from 1929–1933, and 21 export versions of O3U between 1933–1934 and they saw extensive bombing actions. The O2U-1 versions participated in the Central Plains War and in the January 28 Incident against the Japanese targets, while the O3U versions first participated in the Battle of Pingxingguan to support the Chinese ground forces, and later against the Japanese targets in Shanghai.