A clock generation circuit, includes a first current source, a resistor connected to the first current source, a second current source, a first demux circuit connected to the second current source, a second demux circuit connected to the second current source, a capacitor connected to the first demux circuit and the second demux circuit, a first comparator connected to the first current source and the capacitor, a second comparator connected to the first current source and the capacitor, and a RS trigger connected both to the first comparator and the second comparator. The present invention has simple structure, small process variation, and lower cost, and is able to improve the accuracy of the clock with maximum possibility.