An exclusive breastfeeding rate in the first 6 months of life of at least 50% is one of the six World Health Organization global nutrition targets for 2025. However, the exclusive breastfeeding rate in China is quite low and decreasing which makes it urgent to explore effective ways to reverse the current downward trend. As mobile technologies have rapidly developed, mobile communication apps such as WeChat (one of the largest social networking platforms in China) are well accepted and have the potential to improve health behaviors in a convenient way. The current paper describes the study protocol of a WeChat intervention that aims to promote breastfeeding in rural areas in China.