Department of Chemical Engineering in the College of Engineering, University of Al-Qadisiyah held an online symposium on the optical methods of quantitative measurement of heat and mass transfer in energy systems. The online symposium also reviewed the most important optical techniques used in monitoring and testing heat and material transferring processes. The online symposium reviewed methods used in accurate measurement of heat and mass transfer in order to solve the problem of accurate measurement and visualization of heat and mass flow in various applications, as well as reviewing quantitative methods of optical flow and interference measurement techniques in the study. The online symposium demonstrated the basic features, data processing of the proposed optical methods that have been applied in the energy fields in the recent years, detailed principles, fields of application, challenges and future trends.