Different inlet/outlet arrangements are proposed for parallel mini-channels and their effects on the flow distribution and heat transfer are numerically studied. It is found that different arrangements have great impact on the characteristics of flow distribution. The velocity and surface temperature inequalization coefficient are introduced to evaluate the effects of inlet/outlet arrangements. The results show that the velocity inequalization coefficient increases with the rise of flow flux when the inlet/outlet arrangement is fixed. The velocity inequalization coefficient of upper center (UC)-type arrangement is minimum in these numerical cases. And when the channel area is fixed, the velocity inequalization coefficient decreases with the rise of channel numbers. The surface temperature inequalization coefficient increases with the heat power. When the heat flux is fixed, the heat resistance decreases with the rise of heat flux and finally trends to a constant.