Abstract:Plant community coverage was often used as one of factors to describe the structure and importance of plant community.Usually it was estimated by sighting estimation in the field,and this procedure affected the accuracy of measurement of plant community.A useful concept,Foliage Projective Cover (FPC) that means the percentage of the land covered by foliage,was introduced,it had some ecological significances and was suitable for describing horizontal character of plant community.Using simple tool made by us,FPCs were measured at two sites in Xinjiang area.Through ecophysiological model of plant community developed using Stella model tool,we simulated the FPCs at those two sites.Compared with the measured data,we thought that FPC was a useful and an effective method and theory to describe the horizontal structure of plant community in arid area,and it may be used for measuring FPC for all plant communities.