Abstract: Salt cavern is one kind of underground oil storage facility formed by leaching bedded salt or salt dorm. Total gas volume correlate with single cavern capacity and number of caverns. Single cavern storage capacity is determined by maximum pressure and cavern temperature. In process of gas injection and withdraw, natural gas is compressed and swelled and exchange heat with wellbore and salt, this process obey conservation of mass and energy and it can be predicted by establish mathematical model. Working gas volume is determined by operation pressure. Different withdraw time results in different temperature transformation in single cavern and it influences cavern pressure which determine working gas volume. The long time gas with draws, the more stable temperature of cavern and the more working gas can be produced. Different withdraw condition result in different well head and cavern condition, so it needs to simulate cavern operating process and analyzes well head pressure and temperature, because well head pressure and temperature determine ground facility capacity. This paper describes the calculation and operating simulation on the single cavern storage capacity for Jintan Cavern Gas Storage.