School psychology is an important area within psychology, which has a short developmental history in Mainland China. Nonetheless, along with economic advances and social changes in Mainland China, school psychology is developing and becoming more important. Currently, people need to work harder and longer. This places many under pressure that may cause all kinds of mental difficulties and disorders. School psychological services can work with learners and their families for the healthy development of children and adolescents, and is also the fundamental route to prevent and solve mental-health problems in Mainland China. This article explains the significance and the important effects of school psychology in Mainland China, and provides a general account of the developmental history and the status quo of school psychology. It also compares mental health services in Mainland China with those in other countries. The objective of this article is to present an overall description of school psychology, understand new trends, and discuss the need for the future development of school psychology in Mainland China. This article completed a comparative analysis with the USA and considered current practices in Mainland China.