Objective To analyze the changes of serum C-type lectin domain family 11 member A(Clec11a)in the progression of diabetic kidney disease(DKD)and evaluate its value in bone metabolism.Methods The clini-cal data of 184 patients with type 2 diabetes(T2DM)were collected and serum Clec11a levels were detected.Ac-cording to the UACR,patients were divided into non-albuminuria group of 76 cases,microalbuminuria group of 72 cases and macroalbuminuria group of 36 cases.In the same period,50 healthy subjects were selected as control group.The general clinic data,bone mineral density and bone metabolism indexes of all groups were measured.The correlation between Clec11a level and bone metabolism indexes of DKD patients was analyzed.Results Levels of Clec11a and eGFR in all T2DM subgroups were significantly lower than those in normal control group(P＜0.05).Levels of Clec11a and eGFR in T2DM subgroups significantly decreased with the increasement of UACR(P＜0.05).Bone mineral density(BMD)of neck of femur and Clec11a levels in microalbuminuria group were lower than those in non-albuminuria group(P＜0.05).The levels of Clec11a and BMD of lumbar vertebra in macroalbu-minuria group were lower than those in microalbuminuria group(P＜0.05).Bone metabolism indexes such as 25 hydroxyvitamin D[25(OH)D],N-terminal fragment of osteocalcin,amino terminal peptide of type Ⅰ procollagen,parathyroid hormone,and β collagen degradation products were not significantly different between microalbuminuria group and non-albuminuria group.BMD,25(OH)D and Clec11a levels were negatively correlated with UACR levels(P＜0.05).Clec11a had the strongest correlation with UACR.Conclusion Serum Clec11a levels in T2DM pa-tients significantly decreased with the increasement of UACR.Compared with other bone metabolism indexes,Clec11a showed a stronger negative correlation with UACR.Regular detection of serum Clec11a levels for DKD pa-tients is conducive to identify bone loss early.