4-Quinolones have a wide variety of activities such as antibacterial, antifungal, antiviral and antifilarial activities. Recently it was discovered that they have antitumor activity to a wide varieties of tumor cells such as breast cancer, colon cancer and many other. Besides, it was found that the use of 4-quinolones in cancer patients helps in inhibition of cancer cells and also prevent the secondary bacterial infections due to decreased immunity because of the usage of chemotherapy. This book supply new synthetic approaches for synthesis of novel 4-quinolones, computational design of these compounds and their biological assay against breast carcinoma cell line. In addition, it states the structure activity relationship to design a 4- quinolone compound of anticancer activity. Many compounds have shown a very good anticancer activity which is useful to researchers in drug discovery, drug industry, pharmacists, patients and companies of synthesis of active constituent.