China is confronting aggravated ozone (O₃) pollution, leading to adverse health impacts. This study quantifies the regional contributions to O₃ in China using two approaches; estimating ① where goods are produced (the production method), and ② where goods are consumed (the consumption method). The production method predicts higher local source contribution than the consumption method; this difference can be attributed to exports. Occurrence of high-O₃ episodes suggests a major contribution to O₃ concentration as a result of trade activities. Based on the consumption method, 9219 out of 18 532 daily premature mortalities were caused by local sources in north China, while it increased to 14 471 of the production method when neglecting contributions due to export and consumption in other regions. This study suggests that O₃ control should consider both where goods are consumed and emissions are emitted, especially taking account of international trade activities.