Oriented to the development of such network technologies as 3G and NGN and applying the system planning method in information technology systems, this paper conducts research on the Business Operation Support System (BOSS) suited to 3G and how to achieve a smooth transition toward 3G for the mobile business operation support systems, in which a functional framework of this new system along with a fullscale model for the technology framework is established, and a new partition method for the subsystem is proposed.Aiming at the synthetically collecting subsystem, a description of the required functions and an analytical design of business flow are formulated.