The present invention relates to a circuit and a method for controlling a self-refresh cycle of a dynamic random access memory or DRAM. A cell voltage is directly detected so that a self-refresh cycle can be variably controlled. Detectors each detecting whether or not a voltage charged into a capacitor of a detection cell drops to or below a reference voltage and outputs a detection signal. A pulse generator generates a self-refresh pulse while being linked with an enabled detection signal of the plurality of detectors. A self-refresh cycle can be variably controlled and set to be suitable for the charging capacity of a cell. The detection cell is adapted to the change of the charging capacity of the cell in accordance with a change in temperature.