In order to stimulate learning interest among university students towards biochemistry and to improve learning outcomes, we performed a 10-week biochemistry Rain Classroom teaching experiment among students majoring in clinical medicine. Rain Classroom is a plug-in for WeChat, a smartphone instant messaging application. Teachers can post teaching resources on the Rain Classroom platform, administer tests, and communicate with students. Rain Classroom can also be used to automatically collect course learning data from students. When teaching is complete, questionnaire surveys can be conducted, and test scores can be outputted. Results showed that students were interested in the biochemistry Rain Classroom teaching application, and that the application increased their enthusiasm for the course materials. There were significant improvements in the learning outcomes in students given Rain Classroom teaching, compared to those given traditional PowerPoint slideshow lessons. We conclude that the Rain Classroom tool is a new mobile learning application that promotes self-learning and improves learning outcomes in biochemistry learning.