Three kinds of copolymeric emulsions with concentrations up to the extent of 40 per cent were prepared by using a mixed emulsion system of ionic and nonionic emul-sifying agent in emulsion qopolymerization．Copolymeric emuLsiOIlS which had been ireated with cation and anion exchange resins are stable to long-time storage and their residual substance is eomparalble to a standard of nonionie emulsion．TG，DTG. GC-MS and pyrolysis gas chromatographic methods were used to determine the influence of variOUS copolymers．as well as the ratio of its components towards degradation rate．An order of susceptibility of degradation of these copolymers was found．These results may be of a help to finding way for synthesizing of barrier filming materials for color picture tube in aluminized screen techniques．