Abstract: The planar process Si detector is a kind of new type charged particles detector with fineproperties, it is possibly made X-ray detector suitable to the practical applications. In order to re-search into this possibility, detector temperature properties must be studied. In the paper experi-ment apparatus is introduced, temperature properties of the planar process Si detector are moresystematically measured, the temperature range is from -20℃ to +50℃. The results are pre-liminarily analyzed.