<p>Abrasive water jet (AWJ) technology is widely used in many industries such as material processing due to its unique advantages of low cutting force, no thermal effect and no environmental pollution. However, compared to processing techniques such as gas or plasma, the material removal rate (MRR) of AWJ is lower. In addition, kerf taper, which is an inherent defect of AWJ, further limits its application and expansion. Therefore, the influence of input parameters in AWJ machining, including abrasive mass flow, water pressure and traverse speed, on the kerf taper and MRR is studied in this paper. The results indicate that the traverse speed has the largest contribution rate to the kerf taper and MRR, followed by the abrasive mass flow. The water pressure seems to have little effect on the above responses. A higher traverse speed leads to a greater kerf taper and MRR. Increasing the abrasive mass flow can increase the MRR and reduce the kerf taper. In addition, regression models for the kerf taper and MRR are developed and validated, which is beneficial for optimizing machining parameters, improving processing quality and efficiency.</p>