Abstract: Two advanced separating methods have been used for T_3 RIA kit. They are the solid phase microparticle (ms) and magnetizable particle (M). They are not only as simple, accuracy, sensitive, stable, rapid as PEG, but also are not easily interfered by temperature as well as the lower nonspecific bind than PEG. They eliminate the procedure of adding PEG. The quality control index measured by T_3 (ms), T_3 (M) are in the range of requirement: the intraassay CV<5%, the interassay CV<15%. The correlations of the two methods are good with T_3(PEG), P<0. 0005.