Based on delegation of trusted relationship, a ross-domain direct anonymous attestation scheme for wireless mobile networks is proposed. A proxy signature is used for delegation among domains, and the direct anonymous attestation (DAA) method is used for mobile terminal authentication when a terminal roaming to another domain. The remote attestation system is security-enhanced by a key agreement. The authentication protocol is analyzed in Canetti-Krawczyk (CK) model, and the results show that the protocol is secure. Further analysis shows that this proposal can resist reply attacks and platform masquerade attacks; the scheme is effective and suitable for the mobile trusted computing platforms.