This study aims to propose the guideline protection of public procurement corruption in Thailand. Because of the emergence of public procurement fraud in Thailand, the government spending has been used ineffectively. Taxpayers have to responsible for marked up cost of public procurement fraud practices. In-depth interviews were conduct with group of people involved in public procurement process, who are government representatives from The Office of the Attorney General, Office of the National Anti-Corruption Commission, Office of Public Sector Anti-Corruption Commission and Department of Special Investigation. Public procurement officer from Ordnance Department Royal Thai Army and Quartermaster Department Royal Thai Army. Awarded bidder (local and foreign companies) whose have qualified bidder with public contracts. Public procurement experts or specialist from Office of the Council of State and The Central Criminal Court of for Corruption and Misconduct Cases. And public representatives from anti-corruption project of the Office of Public Sector Anti-Corruption Commission. This study reveals the opinions and perspectives from the involved government representatives, public procurement officer, awarded bidder, public procurement experts and specialists and public representatives. The public procurement fraud has mainly resulted from the patronage system in Thailand, which largely contributed to the public procurement policy and guideline that lies on the conflict of interest among certain groups of influential people. Furthermore, the study demonstrates that public procurement corruption in Thailand consider to be the systematic corruption, in which there are misconducts and fraud along the process of public procurement ranging from assessment of public procurement plan, budgetary approval, appointment of procurement committee, supplier qualification, announcement of bidder, purchasing and contracting for work, contract management, inventory control till written material off process. Consequently, the sustainable and long-term public procurement corruption prevention guideline are necessary, which is mainly specified under the Government Procurement and Supplies Management Act B.E.2560 in order to help prevent the fraudulent activities and misconduct practices in public procurement process of Thailand.