Abstract: BSP model is independent of parallel architecture. It is a parallel computing model, as well as a parallel program design model. A horizontal-vertical transaction model based on BSP is proposed, which is suitable for both the long or short transactions and the mixed cases. A process structure for processing transactions in parallel under shared-nothing architecture is proposed, which not only implements the parallelism of both infra-and inter-transactions, but also makes the system available and scalable. A multiversion concurrency control protocol based on timestamp is provided, which fits for this model. Finally, the transaction running procedures in supersteps are described. Performance tests show that both transaction response time and speedup are satisfying when processing transactions.