Aim: To find out the biological activities of thrombolytic, membrane stabilizing activity and also quantification of total phenol content in vitro model from the leave extract of Butea monosperma (B. monosperma) Method: The collected leave was dried and grinded. The grinded powder was kept in 2500 ml of 90% methanol for several days followed by filtered. At reduced temperature 40° C, the volume of filtrated crude methanolic extract was reduced by a vacuum rotary evaporator under reduced pressure. Following the concentrated aqueous methanol extractive was partitioned into petroleum ether, carbon tetrachloride, chloroform and aqueous soluble fractions respectively by the Kupchan methods, Then all extracts were subjected to evaluate in vivo thrombolytic by Daginawala, membrane stabilizing properties by Okoli and Omale method and total phenol content followed by the method of Wolfe et al. Result: In thrombolytic assay among the extractives, petroleum soluble fraction showed the highest percent clot lysis (27.36 ± 0.10%) activity as compared with standard streptokinase (65.15 ± 0.16%). In case of membrane stabilizing activity, crude methanolic extract profoundly inhibited the lysis of erythrocytes (65.79 ± 0.40%) induced by osmosis, whereas reference standard acetyl salicylic acid resulted in (83.147 ± 0.39%) inhibition of lysis. On the other hand, aqueous soluble fraction showed slightly higher level of membrane stabilizing activity in the heat-induced hemolysis (75.3 ± 0.39). In the total phenolic content test, petroleum soluble fraction was found significant level of phenolic (249.06 mg of GAE/gm). Conclusions: This study was conducted to validate the B. monosperma leaves used as a folk medicine (for the ailment of thrombosis, inflammation) such as thrombolytic, membrane stabilizing