This invention is a speed ratio change control device for a belt type continuously variable transmission that a minimum generated pressure of the primary pressure is estimated on the basis of a displacement speed of the movable sheave of the primary pulley and an opening area of a drain side passage of the speed ratio change control valve (S4), an upper limit value of a shift speed is calculated on the basis of the minimum generated pressure (S6), and the target speed ratio is set on the basis of the upper limit value of the shift speed (S10).