Abstract: Based on division of regions of a typhoon and characteristic scales of physical quantities done by Anthes,sets of equations governing different parts of the typhoon are derived with scale analysis and wave energy equations for each part are obtained with the WKB method. Discussions indicated that physical factors contributing to typhoon development are unconstant in all parts of the typhoon,respectively shown as vertical changes in vorticity and tangential wind for the core and outer mid-tropospheric area, or as thermal wind and its deviation for outer planetary boundary layer, or as horizontal gradient of geopotential temperature for outer outflow area.Acting with right moving direction of gravity waves, they may help the energy develop in the typhoon and increase its intensity.