Abstract: In this paper, numerical studes are performed on a model for a coupled standard mapping to investigate the Arnold diffusion. We present estimates diffusion coefficient as a function of coupling constant b, the nonlinearity parameters k and the number of iteration N, and compared with the results of the theoretical. We estimates the diffusion coefficent along the thin stochastic layer of the J-ψ motion. For samll parameter values, theoretical pradiction agrees well with numerical result.