Nozzleless boosters were used to eliminate the risk of nozzle ejection and its complexity in operation, but it accompanies a tremendous drop in performance and requires complex propellant formulation. Eroding nozzle can be used to improve performance in comparison to nozzleless boosters and provides a similar advantage in replacing nozzle ejection. The selection of suitable eroding materials plays a crucial role in determining its performance. Testing of these materials for their erosion rate is possible only if the required high heat flux conditions are met. This testing is more amenable with hybrid rockets than with solid and liquid rockets. The present study is to examine the erosion of a few materials using a lab-scale hybrid rocket motor. The heat flux experienced by the fuel surface is measured using slug type calorimeter. Erosion rates of 4 different materials under these heat flux conditions are reported. A correlation is presented between erosion rate and heat flux for the materials tested.