A system and a method for replicating data among heterogeneous databases are described. The system includes an initialization module for creating and initializing shared memory, a message queue and a semaphore; a processing module including a data reader, a data adapter and a data loader; a replication module for replicating the data in the shared memory to a target database according to the messages in the message queue; and a cleaning module for releasing the shared memory after the replication. The method includes creating and initializing the shared memory, the message queue and the semaphore; reading data from the source database, then converting the data into target data for a target database, and loading the target data in the shared memory; replicating the target data in the shared memory to the target database according to the messages in the message queue; and releasing the shared memory after the replication.