Objective　To explore the significance of GBA gene mutation and gene detection in diagnosis of Gaucher disease. Method　The clinical data and genetic testing results of 3 probands from 3 unrelated Gaucher families and their family members were analyzed. Results　A compound heterozygous mutation of c.907C>A and c.1448T>C was found in the proband of the first family, which was inherited from parents respectively. Another complex heterozygous mutation of c.1174delC and c.1226A>G was found in the proband of second family, which was inherited from parents respectively, and the variant c.1174delC was a new mutation, which has not been reported in the literature according to the search by HGMD. The homozygous nucleotide variation of c.1342G>C and heterozygous nucleotide variation of c.1263_1317del was found in the proband of the third family and the c.1263_1317del heterozygous mutation was inherited from father. Conclusion　The mutation of GBA gene was the cause of Gaucher disease in these 3 families and Gaucher disease can be diagnosed by molecular genetics in clinic.