I encountered the problem with table contains identity primary key field.

When I call session.save(obj), the hibernate inserted this record into table without waiting for transaction commit althought the program called session.beginTransaction() function.

Please show me how to solve this problem.

Best regards,

If you are worrying about insert sql statement being issued to the database, then stop: RDBMS will discard the insert if transaction will be rolled back.
Note: db connection should not be in the autocommit mode and the RDBMS is supposed to support transactions (for example MySQL does not support them without innodb)