Optical code division multiple access(OCDMA) offers all-optical processing,asynchronous access ability,and high potential information security.Passive optical network(PON) provides a solution for last mile bottleneck in optical access network.OCDMA-PON integrates the advantages of OCDMA and technological features of PON.It has great potential in future application of optical access network.In this paper,the theory of OCDMA-PON system and the principle of FBG-based en/decoder are introduced.A transmission experiment is designed with two-dimensional optical orthogonal code(2D-OOC),consisting of four transmitters and one receiver,and the data transmission rate is 2.5 Gb/s.The experimental result shows that in the case of multi-user,the system realizes correct transmission and reaches good performance.