We performed spectroscopic observation of possible supernova in M51 (RA 13:30:05.14, Dec +47:10:11.0). The spectrum exhibits the P-Cyg profile of H-alpha, HeI and CaII IR. The absorption minimum of H-alpha reached 17000 km/s. Those of HeI and CaII did 16000km/s. The spectrum is similar to that of typical Type IIP SN 2006bp at 10 days after its shock breakout. We will continue observations.