A system enabling Transactional Memory with overflow prediction mechanism, comprising: prediction unit for predicting the mode for the next execution of a transaction based on the final status of the previous execution of the transaction; execution unit for executing the transaction in the execution mode predicted by the prediction unit, wherein the execution mode comprises overflow mode and non-overflow made. According to this invention, before a transaction is executed, it is predicted whether or not the transaction will overflow, and therefore, the execution of the transaction which is necessary to determine whether or not an overflow will occur is saved.