Saliva contains constituents that reflect the physiological and diseased state of the human body, and hence could be an non invasive and effective diagnostic tool. Various saliva-based biomarkers for early detection of oral pre-cancer and cancer have been proposed and more than 120 biomarkers of saliva (salivary constituents, proteomic, transcriptomic, genomic, and metabolomic analyses) have been suggested as potential diagnostic tools of oral cancer and pre-cancer diagnosis. This book is about the potential salivary biomarker for detection of oral premalignant disorder and oral cancer based on literature review. This book reviews the existing literature to evaluate the role and significance of Potential Salivary Biomarker for early diagnosis of OPMDs and Oral Cancers and also reveals the most common protein involved in metabolism of cancer.