Abstract: In the quantum mechanics, the parity operator P^ can be expressed by ∫d^2z/π｜z〉〈-z｜、∫dq｜q〉〈-q｜和∫dp｜p〉〈-p｜ By using the Dirac symbol and the completeness of quantum representations, an alternative method is proposed. By this method, these integrations for asymmetric projection operator are realized, and then explicit form of the asymmetric projection operator is obtained

Key words: parity operator, quantum representation, Dirac symbol