The automatic liquid filling system is used in different applications such as production of detergents, liquid soaps, fruit juices, milk products, bottled water, etc. The automatic bottle filling system is highly expensive. Where, the common filling systems required to complex changes in hardware and software in order to modify volume of liquid. There are many important variables in the filling process such as volume of liquid, the filling time, etc. This paper presents a new approach to develop an automatic liquid filling system. The new proposed system consists of a conveyor subsystem, filling stations, and camera to detect the level of the liquid at any instant during the filling process. The camera can detect accurately the level of liquid based on the imaging process technique (Edge Detection Approach). In order to achieve the aim of this work, Arduino board is used as the controller unit in the automatic operation of developed filling system. The developed automatic liquid filling system is designed to be not expensive compared to the other available filling systems on the markets. The system is also easy to operate and user-friendly,where only simple steps are required to operate the filling system or modify the working condition.It was found, based on results, that the Prewitt edge detection is the optimal method that should be applied to obtain high accuracy of results and quick response of developed system.