Abstract: Objective To investigate the effect of different status of thyroid function (hypothyroidism and hyperthyroidism as well a8 euthyroid status)on serum ghrelin and leptin levels.Methods The levels of semm ghrelin and leptin were determined by radio immunoassay in 46 untreated subjects with hyperthyroidism.15 hyperthyroid patients achieved aeuthyroid status after radioiodine ¹³¹I therapy,21 cases of hypothyroidism and 18 cases of normal controls,respectively.Meanwhile,the serum levels of free triiodothyronine (FT₃),free thyroxine (FT₄) and thyroid-stimulating hormone (TSH) were measured by chemiluminescence immune assay.Results (1) The levels of serum ghrelin in untreated hyperthyroidism were significantly lower than those in hyperthyroid patients achieved aeuthyroid status (t=3.21,P<0.01). hypothyroidism (t=3.02,P<0.01) and the normal gruups (t=3.39,P<0.01),but the levels of serum ghrelin in hypothyroidism patients were similar to those in normal groups;(2) The levels of sernm leptin did not differ; (3) Serum ghrelin levels were negatively correlated with FT₃ (r=-0.29,P<0.05) and,FT₄ (r=-0.26,P<0.05),positively correlated with serum TSH (r=0.36,P<0.05);serum leptin levels did not correlate with thyroid hormone.Conclusion The levels of serum ghrelin Welm,differently under different thyroid funotional status and correlated with thyroid hormone,while serum leptin were not.