Abstract: Thermal change and its difference on the optical penetration depth of human benign prostatic hyperplasia(BPH) tissue was measured with a double-integrating-sphere setup at 532nm,670nm,830nm and 1064nm. The optical properties of BPH tissue were assessed from the measurement results using the inverse adding-doubling method.The results of measurement showed that,in exposure temperature range from 20℃ to 80℃,the optical penetration depth of BPH tissue at 532nm,670nm,830nm and 1064nm increased with increase of wavelengths,the optical penetration depth of BPH tissue at 532nm,670nm,830nm and 1064nm varied with a change of exposure temperature by thermal effect,change of the optical penetration depth of BPH tissue at 1064nm was significantly bigger than that of BPH tissues at 532nm,670nm and 830nm,respectively with increase of exposure temperature.Maximal optical penetration depths of BPH tissue at 532nm,670nm,830nm and 1064nm were respectively 0.404mm,0.539mm,0.699mm and 5.917mm at exposure temperature of 50℃,50℃,50℃ and 70℃,respectively,andminimal optical penetration depths were respectively 0.251mm,0.449mm,0.621mm and 1.542mm at exposure temperature of 20℃,20℃,80℃ and 60℃.The results of measurement indicated a few useful reference data for treatment of BPH using optical and thermal properties of laser.