Followinf the year of 1991, with the extensive application in the military field of new and high technology, focusing on information technology, it is a common choice for main countries in the world to build an Informationization army to promote the ability to win an information war in the future. Military information construction has already become the focus topic of military theory innovation and military practice and also an important observation indicator to assess national defense construction and military strength development all over the world. Under this background, Jiang Zemin proposed a national defence and military modernization cross-centennial ¡§three step¡¨ development strategy to promote military information construction in an all-round way and hope to build up an information-based army in 2050. The construction achievement of the first step strategy from 1991 to 2010 is a key factor to the success or failure of PLA building up an Informationization army in 2050. The main study focus and range of this dissertation is PRC's first step national defence and military modernization construction based on cross-centennial ¡§three steps¡¨ development strategy. By studying military thinking logic and law building, including fighting, building, training, we are going to observe and understand the military information construction outcome from 1991 to 2010 of PRC and assess and analyze the prospect of PLA military information construction, the domestic and foreign challenge that they may face, and its impacts on surrounding countries.