To explore the influence of spherical joint with clearances on the dynamic performance of spatial linkage mechanism, a kinematic model of the spherical joint with clearance is established based on the Cartesian coordinates, a spatial four-bar mechanism RSSR is used as an illustrative example and some numerical results are presented. The dynamics model of the RSSR mechanism with spherical joint clearance is also established based on the Lagrange-multiplier method. The dynamic properties of the RSSR mechanism with joint clearance are analyzed, which considered the effect of the size of joint clearance, crank driving speed and joint material. The results show that the difference contact force model of the joint will influence significantly the output result, the contact points of the ball and socket spread mostly in two regions on the clearance sphere, the clearance size of spherical joint affects the dynamic response of the mechanism dramatically. The influence of clearance size on the angel acceleration of the rocker and the contact force of the spherical joint with clearance is non-linearly and positively relation.