We report a point mutation in the TRβ gene in korean patients with generalized resistance and pituitary resistance to thyroid hormone. One mutation at TRβ(P453S) were detected in patient with pituitary resistance to thyroid, which showed different phenotype, generalized resistance to thyroid hormone, in her mothers. But, the other(C31Y), did not show clear relations with the disease. Therefore, further study of molecular and cellular basis will be warranted to explain the clear mechanism of the resistance to thyroid hormone(J Kor Soc Endocrinol 15:113-120, 2000).