This research was the first cytogenetic study of the lesser bamboo rat (Cannomys badius) from Nongbualamphu, Nongkhai, Loei and Udonthani Provinces, Thailand. Blood samples were taken from 8 males and 6 females and then subjected to standard whole blood T-lymphocyte culture. The samples were harvested by colchicine-hypotonic-fixation-air-drying technique and followed by conventional, GTG-, CBG-, Ag-NOR banding and high-resolution techniques. The results showed that the diploid number was 2n=50 and the fundamental number (NF) was 94 in both males and females. The autosomes consist of 12 large acrocentric, 2 medium submetacentric, 10 medium acrocentric, 4 small metacentric, 6 small submetacentric, 8 small acrocentric and 6 small telocentric chromosomes. X chromosome was the largest submetacentric chromosome, while the Y chromosome was small acrocentric chromosome. From GTG-banding and high-resolution techniques, the numbers of bands and locations in the C. badius were 262 and 302, respectively, each chromosome pair could be clearly differentiated. CBG-banding shown C-positive (dark band) on the centromere of all autosomes. However, C-negative (light band) shown on Y chromosome. From Ag-NOR banding, there is no detection of nucleolar organizer regions. All of these results can advantage as the useful basic genetic information for C. badius cytogenetic study. The karyotype formula for C. badius could be deduced as: L₁₂^a+M₂^sm+M₁₀^a+S₄^m+S₆^sm+S₈^a+S₆^t+sex chromosomes.