The relationship between functional diversity vs.species diversity and habitat heterogeneity is poorly understood in forest ecosystems.We evaluated functional diversity measured by the Raos Q in a large stem-mapped forest dynamics plot in a subtropical evergreen broad-leaved forest in China.We analyzed the relationship between functional diversity and habitat factors in order to quantify the relative contribution of topographic factors (elevation,convexity, slope and aspect) to functional diversity, and functional diversity was compared with classic species diversity measured by the Shannon-Wiener index at multiple spatial scales including 10 m × 10 m, 20 m × 20 m, 40 m × 40 m and 50 m × 50 m quadrats.