This project is a study of grid generation by adaptive mesh method in the gulf of Thailand and the upper gulf of Thailand. Using the transformation relation from physical domain to calculation domain. Generate adaptive mesh equation by Euler equation which consider about smoothness orthogonal and weight area variation. Calculate initial grid points by using Lagrange interpolation polynomials. Using initial grid points apply to adaptive mesh method and using single step iteration is name of Gauss–Seidel's method. The results were calculated into errors accepted. The results from calculation can be display on physical domain grid (the gulf of Thailand and the upper gulf of Thailand)