Depending on who you talk to, there were anything from 40-50m smartphones sold in the last quarter, compared to around 19m in the USA. Combining Baidu and CNNIC data, it looks like there were around 180m smartphones in China in Q2, of which 65m were Nokia Series 60 (a rapidly shrinking base), 30-35m were iPhones and about 80m were Android.
FORBES: Android, China and Addressable Markets