Aim and objective: The aim and object of the study is to analyse the invivo antibacterial effect of synthesized compound on albino swizz mice Method: The novel series of quinazoline 2, 3 dione derivatives were synthesized, from the synthesized compounds 5 derivatives were evaluated for invivo antibacterial activity with standard drug ciprofloxacin at 50mg/kg dose. The derivatives were analysed for acute toxicity test and invivo antibacterial test (mouse protective test as per the guidelines). The test were carried out for two bacterial Stains such as S.aureus and E.coli. Result: From the synthesized compound the compound T6 and A6 shows higher level of antibacterial activity and its was estimated that at a dose of 50mg/kg b.w the synthesized compound (T5, T6, A1,A5 and A6) shows no sign of toxicity so safety level was predicted at 50mg dose at the same time the compound T6 and A6 shows higher percentage of protection against S. aureus and E.coli with reference of standard drug ciprofloxacin at a dose of 25mg. Conclusion: The above data reveals that the synthesized compound has antibacterial activity in a dose of 50mg. Compared to other derivatives compound T6 and A6 shows most prominent role in protection activity which means due to substitution of fluro and chloro compounds on the derivatives. In future if further derivatives were synthesized using this novel series it would be a most promising and lead molecule for many disease.