Objective:Investigating thalassemia genotype and constituent ratio in Zhaoqing area.Methods: Specimens were screened first by hematological methods,in which positive samples were further detected α and β thalassemia gene by using gap-PCR and reverse dot blotting method.Results:839 cases of thalassemia were identified among total 8751 cases,479 cases were with α-thalassemia(57.1%);——SEA/αα mainly(75.37%),-α3.7/αα were more common than the-α4.2/αα,the HbH disease also accounted for a substantial proportion(11.9%).339 cases were with β thalassemia(40.4%);which including 10 mutation types and 18 genotypes,the most common types of mutation are CD41-42 / N,ⅣS-Ⅱ1654/N,CD17 / N,-28 / N,CD71-72 / N,account for 89.07%.21 cases were with compound α and β thalassemia(2.5%).Conclusion: Studying zhaoqing area thalassemia genotype and constituent ratio,would be useful for genetic counseling and thalassemia prevention program in this area,it also has great significance for the prevention the birth with severe case of thalassemia.