Selfservice outdoor activity is a social activity, the organizer of which is “a person who takes part in social activities” in the legal sense. In the activities of Hike by going Dutch, heavy obligations to ensure the safety of Hikers should not be created for the Organizer of Hikers, while, in the Hike not by going Dutch, the obligation of Organizer of Hikers to ensure the safety is relatively heavier. Based on that Hikers take part in Hike voluntarily with the composition of adventure, the tort liability of the Organizer of Hikers is reduced. The legal basis of the tort liability taken by Hikers is common provisions, not the principle of equity. Because of lack of “the meaning of effect”, it is not appropriate to consider that there is a contractual relationship between the Organizer of Hiders and Hikers, nor to decide the Organizer of Hikers to bear the liability for breach of contract. In accordance with the method of explaining contracts, insurance companies can not claim that the activity of Hike is an adventure. So the insurance liability can not be released because of such reason.