Abstract: The karyotype, G-banding pattern and Ag-NORs pattern of the chromosomes of Japanese White Rabbit were studied. Its karyotype was 2 n=44.18 m+7sm + 10st+9t. The polymorphism of Ag-NORs was found in the chromosomes of Japanese White Rabbit.The number of Ag-NORs of chromosomes in one cell ranged 1～6 and averaged 2.93. The Ag-NORs were located on the terminals of the short arms of No. 12, 14 and 20 chromosomes. The G-banding pattern coincided generally with other reports.