The properties of plasma-enhanced CVD phosphorous silicate glass (PECVD PSG) for passivation layer are studied . Phosphorous contentration was analyzed with X-ray fluores-cence. As a result, PECVD PSG has a limiting phosphors concentration of about 8 mole%. Curves relating to etcll rate, infrared absorption ratio, and sheet resistivity were adapted to monitor phosphorous concentration indirectly Dielectric properties, step coverage, crack resistance, and gettering effect are discussed in both of atmospheric pressure CVD (APCVO) and PECVD oxide. PECVD SiO2 film have density of about 2.4 g/㎤ at deposition rate of 450$AA$/min, refractive index of about 1.53, and breakdown at fields of II-13 MV/cm. Crack resistance of PECVD oxide is greater than APCVD oxide. PECVD PSG films contained with 2 mole % phosphorous show good step coverage and gettering ability. The obtained results show more advantages in PECVD PSG than in APCVD PSG for device passivation.