In this paper,based on the different vegetation area occupied by the traffic capacity expansion project of Litang-Qinzhou railway,the vegetation biomass losses of cropland,forest land,and grassland were analyzed quantitatively.The results showed that the vegetation area occupied by the project was 308.6 hm²,of which cropland,forest land and grassland accounted for 140.5 hm²,117.2 hm² and 50.9 hm²,respectively.During the 2 year construction period,the total vegetation biomass loss would be 35 607.9 t,of which 4 792.7 t was cropland vegetation loss(13.5%),29 888.3 t was forest land vegetation loss(83.9%),and 926.9 t was cropland vegetation loss(2.6%).294.3 t vegetation biomass would be compensated in the early stage after the vegetation restoration measures took effect, such as slope vegetation protection and stations afforestation.