Abstract: By selecting the developed and undeveloped tropical disturbances in South China Sea summer,we calculated the kinetic energy budget and conversion for the life cycle of disturbances.The results showed that sub grid scale cumulus convection plays an important role in the life cycle of developed disturbance.Apart from the contribution by cumulus convection,the horizontal flux item also has significant contribution to the development of disturbance in the initial stage.By investigating conversion function C(K_χ,K_Ψ),we examined the conversion feature between divergent wind and non divergent wind kinetic energy.It is found that C(K _χ,K_Ψ)increased with the development of disturbance,the principal contribution is C1=f_χ·_Ψ for the C(K_χ,K_Ψ).In lower troposphere,conversion from K_χ to K _Ψ,in upper troposphere,conversion from K _Ψ to K_χ.By investigating the conversion function C(P,K_χ),we examined the conversion feature between potential energy P and divergent wind kinetic energy.It is also found that C(P,K_χ) increased with the development of disturbance.The significant conversion occurred at upper troposphere.