The gelatinization degree， whiteness value， sensory score， cooking characteristics and texture characteristics were used as the quality evaluation indexes of rice cake to investigate the effect of gelation time， temperature and humidity on the quality of rice cake. The optimization process were determined by orthogonal optimization experiment. Under the optimized process， the changes of water distribution and microstructure of rice cake with different gelation time was researched. Result： Gelation time， gelation temperature and gelation humidity changed the quality of rice cake by affecting gelation extent， velocity and water distribution， respectively. The optimal process was gelation time 18 h， gelation temperature 25 ℃， gelation humidity 80%. During the gelation process of the rice cake， the tightly bound water was separated from the end of the cluster structure chain and transformed to the less tightly bound water， and finally dispersed into the environment in the state of free water to deepen the gelation behavior， while specially the less tightly bound water existed as the intermediate between the tightly bound water and the free water. The microstructure indicated that the macromolecular clusters in the texture concentrate preferentially and form small pore structures. When the gelation behavior was almost complete， the structure became compact and continuous wall shape.