On the basis of the second order solution of two-dimensional random gravity waves in finite uniform depth, which is tederived by a perturbation expansion method, the analytical expression of the second order spectrum is strictly deduced, and for infinite depth, the correct form of the kernel function is given for each octant domain. In fact,the present study improves and corrects the generally accepted results obtained by Tick[1959,Journal of Mathematics and Mechanics, 8(5),643-651].