With the concept of security-spot market or security market with measurable space of agents, which was first given by Zhang (1998, 2000), we continue to discuss the existence of equilibrium in such large economies. Under common conditions, we have claimed the existence of equilibrium in incomplete security-spot market with a continuum of traders. Because of the development from complete market to incomplete market, we have not only generalized Aumann’s results in 1966, but also achieved a breakthrough on researching methods.