The epidermal growth factor receptor (EGFR) is under investigation as a therapeutic target for cancers. Colon cancer cell lines are variably dependent on autocrine stimulation of EGFR. This book therefore,examines the effects of a selective EGFR tyrosine kinase inhibitor, Gefitinib (?Iressa'', ZD1839), on proliferation and survival of colon cancer cell lines whose autonomous proliferation is either EGFR ligand dependent or EGFR ligand independent. Using computational approach , different structural analogues were developed for Iressa, how it inhibits the epidermal growth factor kinase ; the studies include nature of the colon cancer and how Iressa work to stop cancer and also explains the ligand binding in EGFR kinase. The consequences help to understand the nature of epidermal growth factor receptor kinase and how to inhibit intra and extra cellular signal. The In-silico properties facilitate more efficient design of screening libraries and serves as a foundation for numerous ADME compound profiling and drug ability assessments along the drug discovery value chain. It also helps to stop the cancer development; a new guideline for the design of inhibitors.