Objective To investigate gene carrier rates,mutation types and distribution characteristics of β-thalassemia among the fetus of couples who carried with the β-thalassemia gene in Huizhou city. Methods For 116 couples carried with the β-thalassemia gene,fetal villus tissues were collected at the first trimester,cord blood or amniotic fluid were collected at the second trimester,and cord blood were collected at the third trimester.Insitu cultivation was performed for cells in amniotic fluid and villus tissues.Hematology and hemoglobin analysis were performed for cord blood.β-thalassemia gene was detected for tissues before and after cultivation or for cord blood. Results Among 116 fetuses,27 cases were definitely diagnosed with severe β-thalassemia which accounted for 23.28% and 56 cases were carriers which accounted for 48.28%.11 types of β-thalassemia mutation and 21 kinds of genotypes were detected and the top four were as followed:CD41-42 (26.51%),IVS-Ⅱ-654 12 ( 14.46%),CD-28 (10.84%),CD17(6.02%).56 cases were single heterozygous mutation which included 9 kinds of genotypes.24 cases were double mutant heterozygotes which included 10 kinds of genotypes.3 cases were single mutant homozygotes which included 2 kinds of genotypes.Rare mutation were detected which were 1 case of CD14-15 and 1 case of CD41-42/43 respectively. Conclusion This study shows the incidence and mutation rates of β-thalassemia among the fetus of couples carried with the β-thalassemia gene,which provides a scientific basis for prevention of thalassemia in Huizhou city.