Abstract: Kapton and FEP Teflon are the important materials of the thermal control of spacecrafts.They are the Orgenic Polymer,which have the excellent physical and chemical properties. However, the charging phenomenon appear on their surface in substorm at high orbit owing to the high insulation of these matersals. So, in this article, the results of evaluation tests of their conductivities in simulated space conditions have been described. And the charging state in orbit can be expected by these regular results.