Abstract: This research focuses on the ability and personality of 1480 middle school students in Shanghai area by Q-type clustering, The results show six main different types of psychological development which is related to the acadermic achievement of the students 353 under achievement students can be divided into four main types temporary hinder, ability hinder, motivation hinder and systematic hinder, Different types of students show different characteristics, This research can lay a foundation for drawing up a practical instruction program for different types of students.

Key words: under achievement, ability, personality characteristics, Q-type clustering