With the rapid development of ultrafast intense laser technologies, the interaction of intense laser radiation with mat- ter has been a frontier for few decades. The International Conference on Multiphoton Processes (ICOMP), initiated in 1977, covers the latest advances in the field every three years. The special issue is based on the spirit of the 13th International Conference on Multi-Photon Processes, ICOMP13, which was held in Shanghai, organized by Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, on Dec. 7-10, 2014. This special issue of Chinese Optics Letters contains a collection of articles originating from the ICOMP13. The con- ference focused on nonlinear optical interaction, multiphoton processes, strong field ionization of atoms and molecules, quantum control of atomic and molecular dynamics, intense laser-field science, laser acceleration of electron and ions, imaging of electronic and nuclear dynamics, XFEL and XUV pulse generation, and laser machining.