This paper concerned on the influence of acoustic velocity change on the pulsed electro-acoustic (PEA) space charge measurement. The space charge measurement results of an air gap and low density polyethylene (LDPE) samples have been compared under different temperature respectively. According to the experimental results, it was found that acoustic velocity of test samples changes with the increasing of temperature, and which would bring distortion into space charge output signals. Moreover, the influence of temperature on the test results was corrected based on the real velocity which corresponding to the working temperature.