The article sketches the direction and importance of cultivating juvenile free defenders in volleyball.

The effect of free defenders become more and more marked in modern volleyball.

Since the official execution of the "libero rules", the libero has become one of the needful players of all volleyball teams and played an important role in the volleyball match.

This paper,besed on video recordings,and relevant statistics and materials,aims to give a comparative analysis of the practical abilities of libero players between Chinese and foreign men volleyball teams.

The methods of literature and on-the-court statistics were used to analyze the body height, the effectiveness of receiving services and defense and the proportion of receiving services of free-defensive elite of our country.

A concept of mark defense in dangerous area is put forward,and the detailed design and implementation of the defensive role is presented in detail.

According to features of complication and variety in a basketball game,the important role of how to nurture a player′s individual defence ability in the basketball game is briefly analysed.