The present invention provides a GOA circuit based on LTPS semiconductor thin film transistor to control the voltage levels of the first node (Q(n)) and the second node (P(n)) with the forward scan direct current control signal (U2D) and the backward scan direct current control signal (D2U). The clock signal (CK(M)) is merely in charge of the output of the GOA unit of corresponding stage, which can effectively reduce the loading of the clock signal. It ensures that the entire loading of the clock signal after the GOA units of multiple stages are coupled to promote the output stability of the GOA circuit, and to realize the forward-backward scan of the GOA circuit. Moreover, the GOA unit of each stage comprises only ten thin film transistors, which is beneficial to reduce the layout space of the GOA circuit and to achieve the narrow frame design of the display device.