Abstract: This paper discusses about the problem of the physical geographical zone in Anhui province in the light of the balance of heat and water in geographical condition,i.e.the radiative aridity index and the radiation balance. According to the formula,the evaporative power E=(δ/(δ+r))(1/L)×0.8Q-(δ/(δ+r))(1/L)R_e+(r/(δ+r))E_a and coefficient K=E/r and R=Q(1-a)-R_e,the radiative can be calculated. Based on the chart showing the radiatative aridity index,the author divide temperature zone with K and natural zones with K,and regards the isopleth of R= 60kcal/cm².yr as the derision between the warm temperate zone and the subtropical zone,the isopleth,of K=1.1 as the division between the deciduous broadleaf forest (brown earth) zone and the northern subtropical deciuous and evergreen broadleaf mixed (forest yellow-brown earth) zone,the isoplth of 0.8 as divesion between the northern subtropical deciduous and evergreen broadleaf mixed forest (yellow brownearth) zone and the mid-subtropical evergreen broadleaf forest (red-yellow earth) zone.Therefore,Anhui province can be diveded into three natural geographical zones:(1)The warm temperate submoist region-deciduous broadleaf forest (brown earth) zone. (2)The northern subtropical moist region-deciduous and evergreen broadleaf mixed forest (yellow-brown earth) zone. (3)The mid-subtropical moist region-evergreen broadleaf forest (red-yellow earth) zone.