Abstract: This paper systematically analyses the preparing technology of the cationic resin AKD size and the factors of the effecting AKD sizing efficency. It was found that the emulsifing temperature and time, the choice of the dispersants, and the charge density of the resin had a great effect on AKD quality. The result shows that the AKD size emulsified with cationic resin has higher charge density, longer storage life and better sizing efficiency, and also no susceptibility to moulds.