To study the protein content in raw milk in China, and analyze the influencing factors.Methods Testing results of protein content included 30 531 raw milk samples, with a range of 12 consecutive months from January 2014 to February 2015 and 18 dairy companies from 17 provinces (municipalities and autonomous regions). The data were analyzed by SPSS 19.0 software. Results The average protein content in raw milk was (3.14±0.15) g/100 g. The average protein content in raw milk of large-scale dairy farms, farming communities and household farmers were respectively (3.18±0.14), (3.07±0.12) and (3.00±0.14) g/100 g. The average protein content in raw milk in big cities from South, West, North, Northeast China, Inner Mongolia and surrounding areas were respectively (3.17±0.14), (3.16±0.14), (3.14±0.17), (3.09±0.17) and (3.09±0.10) g/100 g. The average protein content in raw milk in spring, summer, autumn and winter were respectively (3.09±0.13), (3.07±0.13), (3.21±0.13) and (3.20±0.14) g/100 g.Conclusion The protein content of more than 80% raw milk in China was above 3.0 g/100 g. Protein content in raw milk was affected by breeding patterns, breeding areas and seasons. Fat content, non-fat milk solid content and relative density were positively correlated with protein content in raw milk.