concept of specified verifiers is first introduced into the threshold proxy signature, and a (t,n) threshold proxy signature scheme with the specified verifiers is proposed. In the proposed scheme, any t or more proxy signers can sign a message on behalf of an original signer for the specified verifiers, and only the specified verifiers together are able to verify the validity of the proxy signature. In ordinary (t,n) proxy threshold signature schemes, anyone can verify the validity of the proxy signature. In some applications, however, it is required that a proxy signature could be verified only by the specified verifiers together, that is, no a verifier can gain an advantage of the knowledge of the validity of the proxy signature before the other verifiers know its validity (e.g. tenders, bits). Furthermore, the proposed scheme can also revoke the proxy signature right of the proxy signers delegated by the original signer if original signer needs.