Results of CCD photometry using V and R lters are reported for 33 RR Lyrae stars in M15. The periodicities of some variables have been revised and new ephemerides are given. The Blazhko eect, previously reported in V12, was not detected. Applying the approach of Fourier decomposition of the light curves, the physical parameters of the type RRab and RRc variables were estimated. The cluster is Oosterho type II and the values for the iron content and distance are: [Fe/H]= 1:98 0:24 and d = 8:67 0:41 kpc, respectively. The mean values of the physical parameters determined for the RR Lyrae stars place the cluster precisely into the sequences Oosterho type |metallicity and metallicity| eectiv e temperature, valid for globular clusters. Evidences of evolution from the ZAHB are found for the RRc but not for the RRab stars.