- In this paper, we introduce a new parameter iteration method (P-Iteration for short) which can be applied on Adams-Moulton methods to solve initial value problems. Compared with Jacobi iteration method, it has three advantages: (1) it may significantly implement the stable region of the iterative process such that we can efficiently use the large stable region of implicit formula; (2) it allows large step size h to reduce the number of iterations; and (3) it can enlarge the stability region.