The aim of this study was to assess the effect of heavy metal cadmium on haematological parameter. The Indian major carp Labeo rohita was exposed to sub lethal concentration of cadmium for various exposure periods 10, 20, 30, day haematological parameter on RBC, WBC, and Hg, were measured both in control and experimental fish. During various exposure period’s day. The 10, 20, 30, of RBC, WBC, and Hg levels were significantly elevated in the experimental fish over the control and the WBC level was decreased significantly in experimental fish. Keywords: cadmium, haematological parameter, Labeo rohita.