A dynamic analysis model was established for a 2-stage planet gear train in which manufacturing and assembly errors were considered.The load sharing coefficient of the gear train was formulated.The dynamic characteristics of sharing load were analyzed and some relations between errors and the load sharing coefficient were obtained.The effects of different kinds of error on dynamic load sharing were discussed.The results show that the run-out errors of the first stage planet gear and its bearing have the most significant effect on the load sharing coefficient.The errors have greater influences on the load sharing coefficient of the first stage than that of the second stage.The load sharing coefficients of the two stages are increased with the number of planet gears.