The rationality of joint dangerous act theory shows the skills of legal control,beneficial balance between the inflicted and the aggrieved parties,therefore,it is very important to know exactly the elements of joint dangerous act.

It is significant for avoiding expanding victims scope inappropriately to define the subject of joint dangerous act.

The joint dangerous act system is an important law system in modern tort law.

Joint dangerous action is a very interesting problem in torts, at the same time, it is practical.

The joint dangerous action is one tort committed by several infringers,which causes actual damage but the fault cannot be fixed.

As the fact of injury has already existed and it can be judged that it s caused by several people s common dangerous behavior,but the key to being defined as a common dangerous behavior is that it can t be judged clearly that who was the conductor and it decides that the theory of Uncertain Conductor can provide more complete and clearer theo.

The reasonable theory and legislation of common dangerous behavior can reflect the high skill of balancing the rights and interests between the offender and the injured as well as the internal demand of common dangerous behavior for the perfection of its theory and legislation.

The joint dangerous activity is one of the torts of conspiracy.

Objectively, the joint dangerous activity does not emphasize integrativity of the act but lay stress on the indeterminacy of the infringers.