To provide a continuously variable transmission capable of keeping the driving output ratio in simple and small-sized constitution and reducing the cost.

In this continuously variable transmission 10, the force for enlarging the space of an input pulley 16 is applied by the side pressure of a belt 38, and the force is applied as turning force of a reduction gear train 76. By this turning force, thrust load is applied to a driven helical gear 72, so that the driven helical gear 72 is pressed to the inner wall surface of a housing 14 through a resistance member 82. At this time, thrust support force applied to the driven helical gear 72 and the frictional force in the turning direction become rotation locking force of the reduction gear train 76, so that the space between an input fixed sheave 18 and an input movable sheave 20 of the input pulley 16 can be restrained from being enlarged. Thus, the driving output ratio is kept in the continuously variable transmission 10.