Abstract: A cause analysis is made from perspectives of the fortuitousness, inevitability of sports security, and the safeguard system as well to find out about why the school PE is misplaced so as to provide some theoretic support for PE development in schools. It is found that factors like the fortuitousness, inevitability, the lack of security system, the teachers’ passive psychology, the weak awareness of school-based textbooks have distorted the teaching forms of school PE, which has direct negative influence upon the physical constitution of the adolescents. PE teaching, as the important means to improve the physique of our youths, plays a very important part in deciding the future of our country and the whole nation. The agents and executors of School PE, under the pretence of protecting students’ personal security, are very irresponsible for they have run against the entrusted responsibility of a school by the state in term of the teaching manner on the part of an executor. The embedded crisis not only poses a threat to the PE security but also indirectly impairs the physical quality of the youths