Abstract: To reveal the effect of manufacturing and assembling errors on kinematic accuracy of globoidal indexing cam mechanisms, the method of kinematic reliability sensitivity analysis for mechanisms is adopted. The mathematical model for globoidal indexing cam surfaces with machining error is established based on spatial meshing theory, and the motion error function of the globoidal indexing cam mechanisms is then derived. The kinematic reliability model is proposed by using the motion error function. The sensitivity analytical expressions of the standard deviation of the random errors for the kinematic reliability of cam mechanisms are derived. The numerical example result shows that the main influence factor of the kinematic accuracy of the globoidal indexing cam mechanism is the error of the crossed axes angle between cam and driven plate, and the next is the profile error of globoidal cam.