The area of the law of sports that has received the most frequent judicalanalysis, and that has produced a correspondingly large body of decisional authority, is the liability that may result from injuries sustained in sports activities. The central technical questions raised by the liability cases are actually not very broad, and the questions presented by any given case are quite likely to fall within a very narrow range of applicable legal principles. While this might be viewed to indicate that a discussion of injury liability could be easily, and succinctly, presented, that is, unfortunately, not the case. The most direct type of liability resulting from sports activity is that which arises as a consequence of the injuries suffered by participants. Such injuries may be the result of the zeal of competitive activity at close quarters, but will more often be the product of other forces that are not an ordinary competent of the sport. When a participant seeks to recover for his or her injuries, the most frequent allegation, and claim for relief, will be that the person from whom recovery is sought was negligent. The negligence is conduct that falls below the standard established by law for the protection of others against unreasonable risks of harm. But in sports activities, it is demanded other principles. The sports activities essentially has the risk for the zeal of sports activities itself. In the sports activities, there are 4 types. The first is, for example boxing, wrestling, judo, etc. a combat sports, where one by express consent relieves another of an obligation to exercise care for his or her protection and agree to take the chance of injury from a known or possible risk. The second is where one enters a relationship with another that involves a known risk, The clearest example of this is in sports is the case of the game of ball, like football, baseball, etc. All participants was limited the liability within the rules. The third occurs when one explicitly aware of risk caused by the potential negligence of another, and yet proceeds to encounter it voluntarily. Such assumption is made, for example, by athletes when they participate in athletic contest. Finally, One may proceed to encounter a risk that is so unreasonably great as to render the party guilty of contributory negligence, so that recovery is barred both by assumption of the risk and contributory negligence principles. In such type, the players enjoy sports without physical contact with other participants, expecting reciprocal care to avoid unwanted injury. So it is somewhat improper th adapt the theory of consent of the victim. The general rule of sport activities will inapplicable where the injuredparticipant can establish that the injuries were either the result of other than good faith competition or the product of risks that are not ordinary or inherent in the sport in question. Such factors may be present in several principles. Rules of sport activities, safety regulations, social reasonableness, consent of svictim, tolerated danger, objective duty of care are the principle of exemption of the injuries in sport activities. The negligence in sports activities, the objective duty of recklessness can be derived from the statues, past practices, social norm, logic, empirical rule or judical precedent. However in a sport activities, the rules of sport activities may be the most important source of objective duty of recklessness. As the rules of sport activities enumerate matters that require attention in the entire course of a sport activity, participant’s act against the rules can be treated the breach of objective duty of recklessness. But unless the injury resulted from the act that had gone against rules of sport activities beyond reasonable expectation, the offender should not be found th breach objective duty of recklessness. The rules of sport activities differ from type to type. In so called the type of combat sports, the rules of sport activities, while allowing the participant or the team to make physical attack on the opponent th some extent, focus on diminishing or exemption the possibility of injury. In so called the type of individual sport activities, the rules of sport activities prohibit dangerous act and call the attention of participant to avoid injury. To sum up, the breach of sport activities may be treated harshly and less flexibly in type of individual sport activities than the type of combat sports.