Abstract: By using the Krasnoselskii fixed-point theorem, the author discuss existence of infinite positive periodic solutions for nonlinear systems with parameters and obtain infinite positive periodic solutions, where λ is a positive parameter, a,b: ［0,1］→［0,∞) are continuous function and are not always 0 on any subinterval of ［0,1］,  f,g: ［0,1］×［0,∞)×［0,∞)→［0,∞) are continuous function.

Key words: multiple solutions, nonlinear, system with parameter, periodic solution, fixed-point theorem on cone