Phosphorous-doped nano-crystalline silicon films have been prepared by plasma enhanced chemical vapor deposition(PECVD) system. Detailed results on dark electrical conductivity, Raman spectra, infrared absorption spectra, hydrogen content are presented The doped sample's grain size and it's volume fraction is little related to doped concentration, whereas, the room-temperature conductivity of doped samples changed as doped concentration increased from 10(-4)10(-1); it's value can reach to maximum value of 3.57 Omega(-1) cm(-1) when PH3/SiH4 = 2 x 10(-2). The conductivity activation energy of doped sample is smaller than that of undoped nc-Si:H film and hydrogen content is about 10-15%, also smaller than that of nc-Si:H film.