The heat capacity of a polyimide BPADA-m-PDA sample, prepared by polycondensation or step-growth polymerization method, is reported for the temperature range between 80 and 380 K. No thermal anomaly was found in this temperature range. A complementary DSC experiment was conducted in temperature region from 373 to 623 K. There was no phase change in this temperature range. A glass transition was observed at 492.42 K. To study the decomposition characteristics of BPADA-m-PDA, a TG experiment was carried out and it was found that this polyimide started to decompose at 630 K.