<FONT face=Verdana>In the researches of discrete-time two-person stochastic differential games

the uniform and exact descriptions on information pattern are absent. To solve this problem，the mathematical definitions of information pattern and other related concepts are addressed in this paper firstly

by introducing Witsenhausen’s concepts about information pattern to the discrete-time two-person stochastic differential games. Then the properties of several typical information patterns and the structures of optimal control law of differential game under these information patterns are strictly proved. The concepts and theorems of the paper provide an important theoretical tool for the researches of discrete-time two-person stochastic differential games.