Following a discussion of the specific influencing factors in the power grid planning under high penetration of variable generation and the limitations of existing methods and tools for the planning，the supplementary evaluation indices for the planning，such as the capability of accommodating intermittent generation sources and the security risk index taking into account the cascade process，are presented.Secondly，a method of judging whether the capability of admitting intermittent generation sources is rational or not on the basis of acceptability in terms of economy of the least annual energy outputs of the generation sources and the security of the power grid is presented.Finally，a method of employing a number of assistant software to form，analyze，assess and select the planning schemes is presented.The complex characteristics such as the process of contingency can be taken into account in comprehensive comparison and selection of the power grid planning schemes under high penetration of variable generation by utilizing the above method.It is an effective channel through which to evaluate and choose such power grid planning schemes.