In both time and wavelength domains of the fiber-optic channels,a novel construction scheme of two-dimensional quadratic prime code(2D-QPC)for two-dimensional optical code-division multiple access system is proposed. The designing process of 2D-QPC is given in detail;the autocorrelation and crosscorrelation of 2D-QPC are analyzed based on finite Galois Theory. After that,the system capacity and BER performance of optical code-division multiple access(OCDMA)system employing 2D-QPC as signature code are calculated according to the“HIT”method. The result indicates that 2D-QPC has better auto and cross correlation properties compared to one dimensional synchronous quadratic prime code(1D-QPC)(autocorrelation from 1 to 0,cross-correlation from 2 to 1),and 2D-QPC also has larger system capacity,which is p+1 times as that of 1D-SQPC when they occupy the same bandwidth and have the same bit-rates.