Abstract: In this study, edge emission of homoepitaxial CVD diamond was observed as one of the main peaks in CL spectra even at room temperature. In order to study room temperature edge emission characteristics of high quality homoepitaxial diamond, CL spectra and CL images were investigated at room temperature in details for samples with and without abnormal particles. The edge emission mainly comes from the homoepitaxial diamond areas without abnormal particles. Most abnormal particles are found to induce well-known band A emission at 425 nm. Suppressing the formation of abnormal particles is very important to improve the quality of homoepitaxial diamond.