Abstract: Although the New College Entrance Examination expands students' right to choose, it also puts forward requirements to their choices. This article is based on a sampling survey of senior grade one students in Guangdong Province, one of the third batch of the pilot provinces that adopted the New College Entrance Examination, is aimed to discover those factors that affect students' choice of subjects. Based on theories of career decision and analysis of the data, it is found that the primary factor that determines the student's choice of subjects is the opinions of significant others, including family members, relatives, friends, and teachers. The second is the opportunity factor, including future career and professional needs, etc. The last is the personal factors that reflect one's own advantages and interests. Therefore, it can be concluded that students, to a large extent, are unable to choose independently, so improving students' ability to choose independently has become a top priority. Since students and parents urgently need more guidance and services, it is necessary to establish a systematic guidance system of subject selection. For schools, it is necessary to build a system of curriculum guidance for subject selection in order to enhance students' overall ability of making choices. For the government, it is necessary to set up a service system of subject selection to improve the guidance of significant others such as teachers and parents.