Abstract: Objective To analyze the clinical phenotype and gene mutation types in 3 patients with Gitelman syndrome and summarize the clinical features of Gitelman syndrome. Methods The clinical data of 3 inpatients clinically diagnosed as Gitelman syndrome (GS) were collected. The genomic DNA was isolated from the peripheral blood and performed high throughput sequencing and bioinformatics analysis to analysis the all exons of 36 genes related with hypohalemia. Furthermore, Direct sequencing of PCR products in the mutation sites was performed in all patients and their parents. Meanwhile the Gitelman syndrome diagnosed by gene mutation analysis was searched in Wanfang database and China Knowledge Network to compare the differences of serum potassium and blood magnesium between different gene mutations. Results Three patients manifested with recurrent hypokalemia, metabolic alkalosis, but normal blood pressure. Gene sequencing results showed that compound heterozygous mutation of SCL12A3 in case 1 and homozygous mutation of SCL12A3 in case 2. Heterozygous mutation of SCL12A3 and CLCNKB were found in case 3. A total of 79 cases of Gitelman syndrome with complete clinical data were included in the analysis. The results showed that there was no significant difference in serum potassium and blood magnesium between different gene mutations. Conclusions Gitelman syndrome have diverse phenotype and the final diagnosis still requires genetic mutation analysis. There was no significant difference in serum potassium and blood magnesium between different gene mutations. The blood magnesium reduction group has a serious clinical phenotype