Abstract: In this paper, we will consider following initial value problem of semilinear stochastic evolution equation in Hilbert Space:
dy(t)=[Ay(t)+f(t,y(t))]dt+G(t,y(t))dW(t) y(0)=y₀
where W(t) is a wiener process in H, H and Y are two real separable Hilbert Spaces, A is an infinitesimal generator of a strongly continuous semigroup s(t) on Y,f(t, y):[0, T]×Y→Y, and G(t, y):[0, T]×Y→L(H, Y), y₀:Ω→Y is a ramdom variable of square integrable. We apply theory of the semigroup and obtain two conclusions of uniqueness of the mild solution of (1) which include the corresponding results in[4].