[en] The absolute intensity of vertical cosmic ray muons at sea level with momentum above 0.32 - 1.78 GeV/c at a geomagnetic latitude 25.5⁰N have been carefully measured by means of a narrow angle proportional counter telescope, which can distinguish a passage of penetrating muon. The present spectrum after being corrected scattering, proton contribution and geomagnetic latitude effect, has been compared with the some other spectrum. Our results are in good agreement with Allkofer et al's result. The differential and integral intensity have been found to be (7.30+-0.17)x10^-3/cm² s sr and (3.02+-0.17)x10^-3/cm² s sr (GeV/c), at momentum 1 GeV/c, respectively