The photoacoustic signal and phase angle have been measured for the single crystal of Polybis-(p-toluence sulfonate) of 2,4-(hexadiyne)-l,6-diol(PTS) in the temperature range of 175-225 K based on the photoacoustic effect (PAE.) The jump of photoacoustic signal and phase angle at 200 ±0.5 K was observed. We suggested that the jump can be attributed to the second order structural phase transition in PTS.