With the development of Internet technology and the increasing popularity of mobile terminals, mobile social network service has become a convenient way to publish information and share resource in our daily life. However, there lacks a good tool to control the granularity of information dissemination in social network. This paper proposes a method for information or resource sharing with precision control, which can measure distance of users in mobile social network and obtain the level of relationship between users to determine how much, and to what precision level, of users' information and resource can be shared. The method can provide a friendly way to protect privacy and decrease the network burden in mobile social network. We take the positioning information service as an example to illustrate the feasibility of the method. Experiment results have shown that this proposed method can effectively reduce the amount of published information.