To improve the tribological behavior of TC21 alloy, the chromized layer is prepared on its surface by using the double-glow plasma surface alloying technology.The microstructure, element distribution, hardness and adhesion strength of chromized layer are characterized by the scanning electron microscope (SEM), energy dispersive spectrometer (EDS), hardness tester and scratch tester,respectively . Using the friction and wear testing machine, the tribological behavior of matrix and chromized layer is explored at different tempertures. The results show that the chromized layer is dense, not cracked and well combined with matrix, and its thickness is about 20 μm. The surface micro-hardness of chromized layer is over 1 000 HV0.1 and gradually decreases with the depth. After chromizing, the general friction coefficient and the specific wear rate of TC21 alloy are reduced at different temperatures, which shows that the antifriction and wear-resistance perform better. The main wear mechanisms of matrix are abrasion wear, adhesive wear and oxidation wear at 20 ℃. The wear mechanism is dominated by the abrasion wear at the same temperature. At 500 ℃, the adhesive wear and the oxidation wear become more serious, and the chromized layer wear mechanisms are elamination wear and oxidation wear.