Exemplary gate pulse modulation circuit and sloping modulation method applied thereto are provided. The gate pulse modulation circuit has an output terminal and includes a voltage modulation circuit and a comparator control circuit. The voltage modulation circuit is electrically coupled between a gate power supply voltage and a second voltage and subjected to the control of a sloping control signal to perform a sloping operation and then output a sloped voltage signal. The comparator control circuit includes a comparing unit and a switching unit. First and second input terminals of the comparing unit respectively are electrically coupled to a node and a first voltage. During the voltage modulation circuit performing the sloping operation, a magnitude relationship between a voltage on the node and the first voltage decides on-off states of the switching unit and thereby decides the moment of the first voltage delivered to the output terminal.