Abstract: Objective　To investigate the clinical, laboratory and genetic features of glycogen storage disease（GSD）IXc. Methods　Five patients suspected as liver GSD were included in our study. DNA was extracted from peripheral blood of all the patients and diagnoses were made after target sequencing to nearly 2700 disease causing genes. All detected mutations were confirmed in the probands and their parents. Further analysis was based on clinical features, routine laboratory examinations and treatment. Results　All the 5 patients manifested with severe hepatomegaly, hypoglycemia, moderately to severely elevated liver enzyme levels, hypertriglyceridemia and growth retardation. Four cases showed poor exercise tolerance but with normal creatine kinase (CK) levels. None of the patients showed liver cirrhosis. Growth velocity and hepatomegaly was improved after the uncooked corn starch treatment was initiated. In the 5 patients, 6 different pathogenic or likely pathogenic mutations in the PHKG2 gene were identified, including one reported mutation (p.E157K) and five novel mutations (p.E56X, p.R185X, c.79_88delinsTCTGGTCG, c.761delC,p.R279C). The p.E157K was the most frequently mutation identified (6/12, 50%). Conclusions　The p.E157K mutation is the hot mutation in our small cohort. Main clinical features of our patients include fasting hypoglycemia, impaired liver function，short statures and poor exercise tolerance, without developing liver cirrhosis.