The feasibility for rapid determination of the chemical composition of Pacific oyster (Crassostrea gigas) by near IR reflectance spectroscopy (NIRS) was assessed. NIRS calibration models were developed using 118 sets of C. gigas samples (two to three sets per batch, total of 54 batches, 5–10 individuals per set) collected over 10 mo from seven coastal locations in northeast China. Glycogen, protein, fat, taurine, zinc, selenium, and ash contents of gonad-visceral mass and adductor muscle were analyzed by laboratory-based methods. Freeze-dried samples were scanned by NIRS at 10,000–4,000 cm^-1 and their chemical composition was predicted by partial least squares regression. Results showed that the correlation coefficient of calibration (R_C) was greater than 0.90 for most chemical components tested (except taurine, 0.8266). Similar differences were found in the correlation coefficient and other parameter indices in both cross and external validations for various chemical components. This study indicates that NIRS provides a rapid and accurate method for rapidly determining glycogen and protein contents in oyster meat (R_C = 0.9917–0.9927). The NIRS method is feasible but slightly less accurate for quantifying fat, zinc, selenium, and ash contents in C. gigas (R_C = 0.9164–0.9529).