A drill string bypass circulation system is a reliable tool that helps divert the flow of the drilling fluid from the drill string through side ports into the annulus. Installed in the drill string above the bottom hole assembly (BHA), the system is mostly used to pump aggressive lost circulation materials (LCM) into formation whereby expensive BHA components such as MWD systems and mud motors are saved from any damages through LCM without having to be pulled out from the wellbore.