Jiangsu Avatarget Biotechnology Co., Ltd. 1 article published in JoVE Cancer Research Generation of 3D Tumor Spheroids for Drug Evaluation Studies Wei Hou*1,2, Zilin Zhang*3,4, Jing Zhang3,4, Shihui Xu2,4, Menglan Li4, Xiaoran Li2,4, Zaozao Chen2,3, Cailian Wang1,2 1Department of Oncology, School of Medicine, Southeast University, 2State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, 3Institute of Medical Devices (Suzhou), Southeast University, 4Jiangsu Avatarget Biotechnology Co., Ltd. This article demonstrates a standardized method for constructing three-dimensional tumor spheroids. A strategy for spheroid observation and image-based deep-learning analysis using an automated imaging system is also described.