A questionnaire survey is carried out in ten grid and province graded power companies on the issues such as natural disaster type threatening power grids in China， the characteristic of natural disasters impacting power grids， existing defense techniques for natural disasters， difficulties and problems in disaster defense， and the demand for disasters defense techniques etc. At the same time， results of the survey are analyzed. The content and conclusion of the survey are valuable to research on relative fields. Based on the survey and analysis， it is set forth that there should be further research on issues including the integrated information platform， acquisition and storage of external information of power grids， probability model of the power equipments'failures caused by disasters， analysis and warning for disasters' threatening safety of the power grid， self-adaptive control and decision-making techniques， and life lines project of handling extreme natural disasters， which will boost the power grid's capability to withstand natural disasters.