The measurement of nuclear modification factor, one of the key signatures for the energy loss (known as jet quenching) of fast parton transversing quark-gluon plasma (QGP) produced in heavy ion collisions, has been measured with the CMS detector. As seen at lower energies, the charged particle spectrum in central PbPb collisions is suppressed by at least a factor of five compared to binary scaling around pT = 5-10 GeV/c. Above pT = 10 GeV/c, however, there is a significant rise in the nuclear modification factor, which will be presented out to pT = 100 GeV/c.