Studying population from a genetics point of view for understanding micro evolutionary changes has come into vogue since late fifties. Small Mendelian groups provide the necessary perspective for such population genetics studies as they are small in number, occupy limited area, and more or less represent distinct gene pool. To know the genetic phenomenon within a small Hill Korwa population the present study has been carried out among culturally and geographically isolated Hill Korwa tribe in Jashpur Distirct of Chattisgarh. Total 202 families were taken for investigation on demography, reproductive performances and for necessary blood samples to study their important genetic traits using standards techniques. Out of them 783.26 constitutes the Effective Size. The Admixture Rate for Hill Korwas is found to be 3.24%. Admixture rate was found to be 25.37. Kesingers Index and the selection intensity recorded for Hill Korwas is 0.6268 and Johnston, Kensingers index estimated to I = 0.7205. 7.9% prevalence of β – Thalassaemia trait was recorded among Hill Korwas of Jashpur district Chhattisgarh (2001-02).Wherein not a single case of HbS trait is reported.