E-Institutes of Shanghai Municipal Education Commission (E03004);Shanghai Municipal Education Commission (04DB07, 07ZZ64);Shanghai Science and Technology Committee (03QA14036);The Special Funds for Major Specialties of Shanghai Education Committee NSFC(1067130)
the National Nature Science Foundation(10171067)Shanghai Municipal Education Commission(No.04DB07)the Special Funds for Major Specialties of Shanghai Education Committee.
In this paper, we study the step criteria of numerical methods for delay differential equations, some results on step-length for Range - Kutta methods and linear multistep methods are given.