Abstract: Objective To establish the analysis method of chorionic trophocyte chromosomes and its application in study of early spontaneous abortion etiology. Methods Division metaphase of chorionic trophocytes was obtained by in vitro culture of chorionic trophocytes.Chromosome sections were prepared for analysis of their karyotypes.Incidence of chromosomal aberration in chorionic trophocytes at early spontaneous abortion was observed. Results The analysis method of chorionic trophocyte karyotype was successfully established.Chromosomal aberration was found in 58.3% of pregnant women with early spontaneous abortion. Conclusion Analysis of chorionic trophocyte karyotype is of important value in study of early spontaneous abortion etiology.