Aim The developmental pattern of early heart in drosophila is remarkably similarity that in vertebrate. This reseach aims at approaching genes controlling human congenital heart disease. Methods In order to clone and identify new genes that are involved in drosophila heart development, after establishing the balanced lethal lines, 310 lethal lines were screened with Mab No.3 antibody expressed in heart cells of drosophila. Results 63 of them showedmutant phenotypes. Conclusions After examined with drosophila deficient stocks of chromosome 2 and 3,the cytological positions of 14 lethal lines have been determined. Candidate genes located in these cytological positions are searched and discussed.