A well-structured land surface model NCAR_CLM4.5(Community Land Model 4.5) is evaluated using the observations at a degraded grassland station(Tongyu station) in semi-arid area in China during the Coordinated Enhanced Observing Period(CEOP).Results indicate that CLM4.5 can reproduce the spatial distribution and temporal variation of the radiation flux, water-heat flux, soil moisture and temperature very well.However, the model underestimates (overestimates) the surface absorbed radiation and soil moisture(diurnal variations of the surface absorbed radiation and soil temperature).Under some special atmospheric conditions, for example at the end of August, the model produces large biases.In addition, the simulations(including radiation flux, water-heat flux, soil moisture and temperature) departe largely from the observations in winter, which shows that the parameterization schemes of surface physical processes of CLM4.5 need to be further improved in winter.