The invention relates to an information sharing method of a mobile terminal, the mobile terminal and a system. The method includes an organization terminal sending social activity invitation requests to invited terminals, adding the invited terminals to a social group built in advance, and sharing related social information with the invited terminals in the social group. According to the method, the mobile terminal and the system, the social group is built through the mobile terminal, a user can complete a plurality of functions such as related activity information records, invitation or addition of the social group, reminding of social activities, map navigation, checking of member information and sharing of activity pictures or videos in one social activity by using the mobile terminal, therefore user operating coherence and user experience are greatly improved, and the problems of dispersed, complex and repeated using functions of mobile terminals in social activities in the prior art are solved.