Logix gear is a new gear based on new tooth profile theory. On the primary, the forming principle of the logix gear tooth profile is analysed. Then the tooth profile curve equations of logix gear are derived, and their center coordinate equations of base circle are given. According these equations, their curves are simulated using Matlab, which are corresponded to practical tests. The study lays a foundation of computer aided design of the logix gears. And the study can be used to perfect mathematical models and to optimize manufacturing methods.