OBJECTIVE: To study the distribution of common α-thalassemia gene deletion in children. METHODS: Blood cell analysis was performed on children who visited the clinic of the Foshan Women and Children’s Hospital. Blood samples (2 mL, EDTA anticoagulant) was collected from children with MCV＜82 fl for analysis of α-thalassemia gene using the GAP-PCR method. RESULTS: MCV＜82 fl was found in 1341 children. Of the 1341 children, 471 (35.1%) were diagnosed with α-thalassemia. The prevalence of α-thalassemia increased with increasing age. --SEA was a major type of α-thalassemia gene deletion (75.3%), followed by -a3.7 (17.0%) and -a4.2 (7.7%) in the 471 patients. The top three genotypes were --SEA/аа (73.2%), аа/-а3.7 (12.5%) and --SEA/-а3.7 (5.5%). CONCLUSIONS: Genetic testing is necessary for the diagnosis of α-thalassemia in children with MCV＜82 fl. --SEA is a common type of α-thalassemia gene deletion, and -SEA/aa is a common gene type of α-thalassemia in the subjects of this study.