The performance of normalized throughput in wavelength division multiplexing (WDM)+optical code-division multiple-access(OCDMA) system was studied.Upper bound of normalized throughput is obtained when all simultaneous users are equally allocated to different wavelength channels.Lower bund of normalized throughput is obtained when all simultaneous users are first allocated to same wavelength channels.The performance of WDM+OCDMA system is compared with multiple-wavelength(MW) OCDMA system when the simultaneous users are equally allocated to different wavelength channels.Analysis result shows that both systems have comparable performance of normalized throughput when traffic load is light.However,WDM+OCDMA system has better performance when traffic load is heavy.Furthermore,the maximum normalized throughput of WDM+OCDMA system is larger than that of MW OCDMA system.