Serum contents of triiodothyronine （T3）

tetraiodothyronine （T4）

reverse triiodothyronine （rT3） and thyroid - stimulating hormone （TSH） and changes of structures of the thyroid gland in the rat of exces - heat syndrome and deficiency - heat syndrome were observed with radioimmunoassay and electron microscopic technique

respectively. The rats of excess - heat syndrome and deficiency - heat syndrome were established with administration of Chinese herbs. Results indicated that serum T3 and T4 levels increased and the rT3 level tended to decrease in the deficiency - heat group

and thyroid follicle epithelial cell had more significant changes as compared with that of the excess - heat group. It is suggested that changes of hormones and ultra - microstructures of the thyroid can be served as an important basis for heat syndrome of deficincy type and excess type.