It has been knowm that pulmonary diffusing capacity was related closely to body size.In this study, a stepwise multiple regression analysis was used to isolate the morphological indices that accounted for the significant proportion of variances of pulmonary diffusing capacity (D_L) and its compoments, diffusing capacity of pulmonary capinary membrane (D_M) and pulmonary capllary blood volume (V_c), under the various conditions