Abstract: To provide and accumulate cytological data for bramble breeding in China, karyotypes of 8 Raspberry cultivars and 7 Blackberry cultivars introduced from foreign countries were investigated in the article. The results showed that all the 15 bramble cuitivars were of euploids and no aeuploids were found. All the 8 Raspberry cultivars were found to have 14 chromosomes, and the karyotype formulae of 2n=2x=14=14m, 2n=2x=14=14m (2SAT) and 2n=2x=14=14m (4SAT) were found respectively in 4 cultivars of ‘Algonquin', ‘Reveille', ‘Dinkum' and ‘Ploana', 3 cultivars of ‘Chilcotin', ‘Nova', and ‘Bristol', and cultivar of ‘Chilliwack'. In the contrast, three various chromosome numbers of 28, 42 and 49 were found in the 7 Blackberry cultivars, their karyotypes formulae were as follows: 2n=4x=28=28m for ‘Arapaho', ‘Shawnee' and ‘Navaho'; 2n=6x=42=38m (6SAT) + 4sm for ‘Ollalie'; and 2n=7x=49=49m for ‘Black Butte', ‘Boysen' and ‘Kotata'. The karyotypes of all the bramble cultivars,except that of ‘Ollalie',which was composed of metacentric chromosomes and submetacentric chromosomes and had a karyotype asymmetry type 2A, were composed of metacentric chromosome with type 1A asymmetry. Chromosome numbers of 9 bramble cultivars ‘Algonquin', ‘Chilcotin', ‘Reveille', ‘Chilliwack', ‘Nova', ‘Ploana', ‘Dinkum', ‘Bristol' and ‘Black Butte' and karyotypes of 15 bramble cultivars were reported for the first time.

Key words: bramble cultivars (Rubus), chromosome number, ploidy, karyotype