Abstract: An ASA new-type emulsifier P-DAVM was synthesized. It had block structure, apparent hydrophobieally associating property and surface activity. Viscosity analysis of ASA latex showed that suitable content of MBA in P-DAVM is 2, 00%. Stability analysis of ASA latex showed that stability of ASA latex could be apparently improved by introdtucieg MBA into P-DAVM. The ASA latex emulsified by P-DAVM remained unbroken in 24 h under room temperature. Handsheets sizing experiment showed that suitable ratio of ASA and P-DAVM was 1: 1. in this ratio and at ASA dosage of 0. 10%, Cobb 60 of the handsheets could reach 24.75 g/m2. Thus the sizing requirement of common wriling paper was satisfied. When it was as ASA emulsifier, P-DAVM could cover the shortage of conventional ASA emulsifier, and had widen the application field of HAWSP.