In order to develop Air Defense Posture, now, Indonesian Air Defense Artillery (ADA) on the prosess of weaponry modernization that carried out by purchasing new modern weapons to replace the old weaponry which is not feasible to operate, and by developing the ability of old weaponry which is still have feasible to operate. 57mm AA Gun system as the part of old weaponry is the most populate Air Defense Artillery weapon that now operated by ADA unit. 57mm AA Gun fire unit still have a good condition to operate, but this AA Gun system don?t have all ADA function such as detection, identification, tracking, and destruction to air target. Therefore, need to be analized how implementation of weaponry modernization, the support and inhibit factors, and formulation of the proper modernization strategy. This research is carried out by qualitative desciptive metode. The result of this reasearch indicate that the need of 57mm AA Gun system modernization is modernization of detection, identification and tracking systems; modernization of AA Gun control system; modernization of C4ISR system; and the modernization of mobilisation system. In order to fill the need, several programs heve been implemented including Defense Research and Development Program (Litbanghan) and Defense Industry?s Techlonogy Development Program (Bangtekindhan). So that several Defense Products have been created such as ADA Surveillance Radar, ADA Mobile Command Post, and New Rebuilding of AA Gun Fire Group equipped with Fire Control System. However, to be operated by users, these products still need improvement.