Cytogenetic studies of five langur species using conventional banding pattern were investigated. All species studied have an identical number of 44 diploid chromosomes, they are assumed to have common evolutionary relationships. For in depth study, molecular markers were assessed using the Amplified Fragment Length Polymorphism (AFLP) method. With seven successful primer combinations, a total of 1043 scorable bands were generated. The percentage of polymorphic bands for each primer ranged from 48.60 to 94.12%. The resulting bands were used for dendrogram construction. From the dendrogram, the individuals of Trachypithecus species are grouped into two major clusters, T. phayrei is clustered with T. obscurus, while T. cristatus is clustered with T. francoisi. The bootstrap value between two groups is 94%. The other cluster, Presbytis femoralis is separated from the Trachypithecus species with a bootstrap value of 94%. Averages of inter-specific genetic similarity values among all langur species studied are 70.16% (between T. obscurus and P. femoralis) to 88.12% (between T. phayrei and T. obscurus). In summary T. phayrei might be a subspecies of T. obscurus. The development of specific molecular markers of a species is beneficial for genetic differentiation of this group of primates.