The present work has dealt extensively and systematically with the effect of ambient temperature on the relative sensity of paramagentic centres for DL-alanine dosimeter during irradiation under the conditions of some other affecting factors unchanged. The average temperature coefficients obtained are 0.00252, 0.00222 and 0.00237℃,-1, for the total doses of 10,5,10,4, and 10,3,Gy respectively. The data are instructive not only in practical use of alanine/ESR dosimetry as a transfer dosimeter but also in examining the mechanism on formation of paramagnetic centres.