Abstract: A dynamic analysis approach is provided to investigate the load distributions among contact bearings of double circular arc helical gears and a computer program is worked out for calculating the load distributions.The dependences of load distribution variation on the main factors are analyzed through a series of parametric studies.It can be concluded that the variation of the rotational speed of the gears has no effect on the load distribution factor in conventional range of rotational speed;However,the load distribution factor can be reduced by decreasing the contact ratio,increasing the transmitted torque as well as improving the gear accuracy;the load distribution factor has a peak which changes with the increase in the helix angle at the same transmitted torque and contact ratio.