Abstract: ob＜x＞jective To analyze the gene frequency and phenotypes of children with 21-hydroxylase deficiency (21-OHD), and to investigate the phenotype-genotype correlation of these patients. Methods We retrospectively analyze clinical information and biochemical results of patients in Xuzhou Maternity and Child Health Care Hospital from June, 201 6 to June, 2019. Genomic DNA was extracted from dried blood spot for mutations of CYP21A2 gene by Sanger sequencing and MLPA. Results In the 16 21-OHD patients, we found 8 pathogenic mutations, including c.293-13C>G, c.518T>A, Exon1-7del, Exon1-3del, c.1451_1452delinsC, c.1333C>T, E6 Cluster, and c.1273G>A , which all were biparently inherited. Among these mutations, c.1333C>T has not been found in Chinese populations until know. In this affected children, the most common mutation was c.293-13C>G (33.3%), following by c.518T>A (28.1%) and Exon1-7del (15.6%). Of these patients, the phenotypes of 8 patients can be predicted as salt wasting (SW), the consistent rate between the predicted phynotypes and acutal phynotypes was 100%. The phenotypes of other 8 patients can be predicted as simple virilizing (SV), with the consistent rate of 87.5%. Conclusion In this study, the phenotypes of children with 21-OHD were SW and SV. The common mutations in CYP21A2 gene were c.293-13C>G 、c.518T>A, and Exon1-7del. The genotypes of CYP21A2 has a good correlation with the actual phenotypes.