As a part of research for rising the quality and developing the new uses of the talc powders, we developed the new preparation method of the pitch control agents controlling effectively the contents of organic-viscous materials(namely "pitch") acted as a main trouble factor in the paper making process of paper industry by washing out the impurities included in the surface or inside of the fine-grinding talc powders with the aqueous solution of HCI, first and the seconds by modificating the surface of it in type of dry or wet with dispersants or retention aids. In this report, it was made an offer the basic data came to the hard core technology concerning the surface modification of the talc powders and discussed the results in the test of application to the pitch control agents of the surface-modificated talc powders.