To identity genetic markets, chromosomal morphology and structural patterns were analyzed by centromeric index and relative length in several swine breeds. The peripheral blood cells which were collected from the jugular vein were cultured and chromosomal morphology was analyzed from 50 Yorkshire, 50 Landrace, and 50 Duroc individuals. The morphological patterns of swine chromosomes consisted of metacentric, submetacentric, and acrocentric chromosomes. The number of swine chromosomes was 38(2n) which included the sex chromosomes XX or XY, and 36 autosomal chromosomes. In temps of relative length, the Y chromosome was shortest and the number 1 chromosome was longest at 1.9% and 11%, respectively. There were significant differences in relative lengthes among Groups III, IV, and Y chromosomes. The chromosomes of Landrace had a tendency to be longer than other breeds in Group III. In Group IV and Y chromosome, the chromosomes of Duroc were longer than other breeds. According to the analysis of centromeric index, the chromosomes were submetacentric and metacentric in Group I, acrocentric and submetacentpc in Group II, metacentric in Ciroup III, and telomeric acrocentric in Group IV. Sex chromosomes were metacentric with a centromeric index of 40% in X chromosome and 49.4% in Y chromosome. There was a significant difference in the centromeric index of chromosomes 1, 6, and 9. On the other hand chromosome 7 had the highest coefficient of variance in centromeric index. This indicated a possibility of polymorphism among individuals.