The study was aimed to determine phenotypic and allelic frequencies of ABO & Rh (D) blood types; and also to ascertain the pattern of variation of ABO blood types across the sex and generation among the Santals of Purulia District, West Bengal, India.

After proper ethical approval blood samples were collected from randomly selected 260 participants (130 of each sex). The participants were divided into three generation, ≤20 years age group as generation-III, 21-44 years age group as generation-II and ≥45 years age groups as generation-I. ABO and Rh(D) blood types were determined by the antigen antibody agglutination test of direct slide method. For statistical consideration chi square test was used at 0.05 significant level (p < 0.05).

Out of 260 individuals 25% was ‘A’ blood type, 36.15% ‘B’ blood type, 25.38% ‘O’ blood type and 13.47% ‘AB’ blood type. The allele frequencies found were 0.21, 0.29, and 0.50 for A, B and O, respectively. In that population phenotypical and allelic frequency changed across the generations, however, this change is statistically non significant at p<0.05 level.

In respect of Rh(D) blood type no such variation was observed, as none of them were found to be Rh(D) negative.