This paper presents a brief work about numerical method to solve ODE with IVP. In this paper firstly derived the first and second order R-K method, than a comparative study will be done use the MATLAB program by taking an example, also in this paper we will show that the second order R-K method is more accurate than first order. Also in this paper present that the accuracy of the methods depend to step size, if the step size taken small then all the numerical methods will be convergence.