This study focuses on the development of a quadrotor research platform with effective obstacle avoidance system using Bug Algorithm. The quadrotor system consist of a DJI frame with a Crius All-in-One Pro as a flight controller with an Arduino Mega2560 to process the data from the sensor. It is also equipped with four ultrasonic range finders to provide the sensing for collision avoidance. Bug Algorithm was chosen due to its simplicity and effectiveness in implementation of obstacle avoidance applications. The results shows that the quadrotor system is able to perform basic flight maneuvers and that the collision avoidance system was able to protect the quadrotor from hitting objects in its environment.