Stochastic differential equation is established by solving some stochastic phenomenon. Square-meanasymptotically almost periodic solutions of the equations are used more widely than square-mean almost periodic so-lutions. In order to study the applications of square-mean asymptotically almost periodic processes in the stochasticdifferential equations，the existence and uniqueness of square-mean asymptotically almost periodic solutions to aclass of stochastic integro-differential equations are discussed using the properties of square-mean asymptotically almost periodic functions and Banach fixed point theorem.