This book is very useful for the researcher and academia who are working on Quinazoline derivatives. This book is also deals with spectroscopic characterization of synthesized Quinazoline. This books contain one separate chapter for antimicrobial activity. All synthesized compounds were tested for their microbial screening. The synthesis of Quinazoline was carried out by condensation with various aromatic aldehydes with 1,3 diketone and acetamidine. Synthesis was made using by HCl as catalyst. All the prepared compounds were characterized in by 1H NMR, 13C NMR, IR, MASS spectroscopic techniques. Biological evaluation of mention compounds was also made in terms of gram positive bacteria such as Staphylococcus aureus, Bacillus megaterium and gram negative bacteria Escherichia coli, Proteus vulgaris.