The effects of reduction temperature and heat preservation time on distribution of Sn and impurity elements during the reduction smelting process of complex tin concentrate were studied. The results showed that Sn, Fe, Pb, Cu, Sb and Bi mainly entered the metal phase, while Al, Si, Ca and Mg mainly entered the slag. The distribution rate of Fe in the metal phase increased with increasing of reduction temperature and prolonging of heat preservation time, and the distribution rates of Pb, Sb and Bi decreased gradually, while the distribution rate of Cu almost remained unchanged. The distribution rates of Al, Si, Ca and Mg increased slowly with increasing of reduction temperature, whereas prolonging of heat preservation time had no effect on their distribution rate. The optimal reduction temperature and heat preservation time for Sn reduction were 1648 K and 120 min, respectively. Under the conditions, the distribution rates of Sn, Fe, Pb, Cu, Sb, Bi, Al, Si, Ca and Mg in metal phase were 93.97%, 75.03%, 63.11%, 97.28%, 50.59%, 59.52%, 1.09%, 0.70%, 0.69% and 0.34%, respectively, and their distribution rates in slag were 1.20%, 19.35%, 2.42%, 0.58%, 14.81%, 12.33%, 96.93%, 98.49%, 95.23% and 94.62%, respectively. Increasing of reduction temperature was beneficial to Fe entering into metal phase, and Sn and Fe had the tendency to be gathered in different areas of metal phase. However, the distribution of Fe in the metal phase would be much more dispersive with prolonging of heat preservation time.