An electronic transmission control system for an automotive vehicle with a belt-type continuously variable automatic transmission comprises a transmission ratio control device including a first motor-driven oil pump supplying working pressure directly to a secondary pulley actuation chamber, and a second motor-driven oil pump supplying working pressure directly to a primary pulley actuation chamber and enabling working oil to come and go between the primary and secondary pulley actuation chambers therethrough. A first control section is provided for controlling the first motor-driven oil pump with feed-forward compensation for the working pressure supplied to the secondary pulley actuation chamber, based on changes in a flow rate of the working oil coming and going between the primary and secondary pulley actuation chambers, so that the secondary pulley pressure is regulated as a belt capacity holding pressure needed to hold a belt capacity of the drive belt in a first motor-driven pump side. Also provided is a second control section controlling the second motor-driven oil pump, so that the primary pulley pressure is regulated as a belt capacity holding pressure needed to hold a belt capacity of the drive belt in a second motor-driven pump side and so that a required value of a speed-change flow rate of the working oil coming and going between the primary and secondary pulley actuation chambers is obtained.