This paper aims at a systematic approach to morphologically characterize of five types of white blood cells (WBC), and its nuclei from light microscopic image of blood samples. Hence, cellular and nuclei based geometric features are computed and analyzed statistically with t-test to show their discriminating potentiality among the species. In morphometry study, the length and breadth along with nucleus of leukocytes are compared between and within the species using oneway Analysis of Variance (ANOVA) followed by Tukey’s pairwise comparison tests. In this study, the estimated values of Rattus rattus and Rattus norvegicus with respect to sex were compared