In order to investigate the effect of flange lubrication on the wheel wear, tracking test in one metro line was made on the trains equipped with flange lubricator and the ones without flange lubricator. The results showed that for the tested line the wheel flange wear occurred in the range from -40 mm to -30 mm relative to nominal rolling circle with concentrating in the root of the flange, and wheel tread wear occurred in the range from -30 mm to 60 mm. The flange lubrication had little influence on the flange thickness, flange height, and tread wear rate in this metro line, as well as the flange wear area rate of trailers with the wheel profile of LM30, but it could greatly slow down the flange wear for motor cars and trailers with the wheel profile of LM32. By comparison with the trains without flange lubricators, the flange wear rate could decrease 24% for the trains of which only motor cars installed flange lubricators, and 36% for the trains of which all the cars installed flange lubricators. For extending the life of wheel, flange lubricators should be equipped on all the car of the train.