This invention discloses a type of stepper motor driver integrated circuit, comprising of a control logic circuit module and a connected stepper motor driver circuit module. The outputs, in groups of two, of the stepper motor driver circuit module are connected to the two ends of coil windings in the stepper motor. Its characteristic is that it is equipped with an I2C serial bus connection which allows the main controller of I2C bus to directly connect to the control logic circuit module via the SDA, SCL, and GND lines resulting in duplex data transmission. With fewer number of signal ports, more driver integrated circuits can also be connected to the same I2C bus. Each driver integrated circuit can directly drive a stepper motor and it can also drive different numbers of stepper motors using different channels. In particular, the multi-channel stepper motor driver integrated circuit has fewer input contact points and thus it clearly reduces the chip area as well as the manufacturing cost which allows the chip to be used in a wide range of digital equipment and electronic information products where space is limited such as with cellular phone photo modules.