Objective To investigate the relationship between FGF23 and Klotho in GD patients. Methods From March 2016 to November 2016, forty-three newly diagnosed and untreated Grave disease patients (GD group) and 27 healthy subjects were selected. Meanwhile,Peripheral venous serum was collected to detect serum calcium, phosphorus and thyroid function in GD group. The levels of FGF23, Klotho protein and 1 in each group were detected by enzyme-linked immunosorbent assay ( ELISA ) . The expression levels of FGF23,Klotho protein and 1,25-dihydroxyvitamin D3 were detected by enzyme-linked immunosorbent assay ( ELISA ) . The differences of FGF23, Klotho protein, 1, 25-dihydroxyvitamin D3, serum calcium and phosphorus between GD group and normal control group were compared,and the correlation between each index was analyzed. The relationship between FGF23 and Klotho protein and the pathogenesis of GD was explored. Results ( 1) Thyrotropin in thyroid function was significantly lower in GD group than that in normal group,and the difference was statistically significant ( 0. 003 ( 0. 002, 0. 004 ) mU/L vs. 1. 650 ( 0. 81, 2. 14 ) mU/L, Z=- 7. 587,P<0. 05] . Thyrotropin receptor antibodies,free triiodothyronine and free thyroxine in GD group were significantly higher than those in normal group. There were [ thyroid stimulating hormone receptor antibodies:9. 03(3. 89,21. 29)) U/L vs. 0. 60(0. 38,0. 97)) U/L,free triiodothyronine:23. 36(11. 61,38. 00)) pmol/L vs. 4. 63(4. 03,4. 92)) pmol/L,free thyroxine:4. 34(33. 94,100. 00) pmol/Lvs. 17. 69(15. 80,20. 35) pmol/L;Z=-6. 694,-6. 878,-6. 836,P<0. 05];( 2) The serum levels of FGF23,Klotho and phosphorus in patients with hyperthyroidism were significantly higher than those in the normal group,and the difference was statistically significant [FGF23:(524. 2±66. 7) ng/L vs. (467. 2±64. 5) ng/L,Klotho:8. 29(6. 89,11. 37) pg/ml vs. 6. 69 (6. 36,7. 53) pg/ml,phosphorus:1. 33(1. 03,1. 52) mmol/L vs. 1. 02(0. 84,1. 20) mmol/L; t=3. 517,Z=-3. 936,-3. 795,P<0. 05]. The Results of correlation analysis showed that: (1) There was no correlation among FGF23 and Klotho,thyroid stimulating hormone receptor antibody,free thyroxine,1,25-dihydroxyvitamin D3,phosphorus and calcium a ( P>0. 05);( 2) There was no correlation among Klotho and thyroid stimulating hormone receptor antibody, free thyroxin, 1, 25-dihydroxyvitamin D3, phosphorus and calcium ( P>0. 05 ) . Conclusion The elevated expression of FGF23 in GD may be involved in the pathogenesis of GD, and the elevated expression of Klotho in GD may be due to the abnormal immune status in GD patients,which may play a protective role.