Abstract: The patterns of G-，C-band and Ag-NORs in Zmu-1：DHP guinea pig were observed. The results showed that the G-banding pattern was varied in the numer and position as compared with those in other stocks of guinea pig. The C-banding pattern was similar to those in other mammals. The Ag-NORs were located on the terminals of the short arms,and were 8 in number in most marrow cells. The results suggested that the chromosome karyotype of Zmu-1：DHP guinea pig has varied from those of other stocks of guinea pig.