Abstract: The tribo-dynamic behavior was considered into finite line contact elastohydrodynamic lubrication (EHL) model for involute gear, which took the oil squeeze effects and friction into account. The multilevel method was applied to solve the complicated model. Comparisons were given between the results from dry rough surfaces and lubricated condition. The results show that the dynamic load was close to static force at low speed except some visible impacts at the transition points. As speed increased, dynamic load changed more smoothly. Compared with dry rough result, the lubricant film could lower the pressure peaks and the pressure built at inlet and outlet. Meantime, the hollow parts between two asperities had higher pressure with lubrication. Pressure reached its maximum value around the pitch point while the film thickness grew slowly under dynamic load.