The construction of diversified courses is an important means to deepen curriculum and teaching reform in general senior high schools, meet the needs of students’ comprehensive and individualized development, promote the professional growth of teachers, and highlight the characteristics of running schools. This paper divides the development of diversified courses in general senior high schools in China since the 1990s into three stages: preliminary exploration, standardization and enrichment, and system construction. It also focuses on objective analysis of the contents of the courses, the educational value, and the operational mechanism, and gives solutions to the problems at the present stage from the following aspects: implementation of the national curriculum program, optimization of the school-based characteristics of the courses, enhancement of the teachers’ curricular literacy, improvement of the evaluation methods, and guidance for the development of the students. It provides practical ideas and methods for the current problems at this stage in five aspects: implementing the national curriculum program, optimizing the school-based characterized curriculum, improving teachers’ curriculum literacy, improving evaluation methods, and integrating guidance for students’ development.