A total of 101 crossbred swamp and murrah buffaloes consisted of F1 50%murrah (n =6), F2 25%murrah (n=11), F2 75% murrah (n=78) and F3 87.5%murrah (n=6) were used for investigation on karyotype by lymphocyte culture and Giemsa staining technique. It was found that F1 crossbred possessed only one type of 2n=49, while for the F2 25% murrah it had 2 types, 2n=48 and 2n=49 with the ratio pf 1:1. The F2 75%murrah had also 2 types, but different karyotypes of 2n=49 and 2n=50 with the ratio of 1:1. The F3 87.5%murrah possessed the same karyotypes as those described for the latter. These findings conform to the theory of cytogenetics. Investigation on phenotypes of these crossbred buffaloes, F1 25%murrah (n=10) and F2 75%murrah (n=52) revealed that the differences of body skin color, body hair coat, hair on the front, end of the tail and on metacarpus and metatarsus as well as the chevron beneath the neck were not correlated to the karyotypes, but depended significantly on percentage of breed. Swamp-like phenotypewas observed in 25%murrah crossbred and murrah-like phenotype in 75% murrah crossbred.
