This is the proceedings of the conference 'Primitive Forms and Related Subjects' held at Kavli IPMU, the University of Tokyo in February 10-14, 2014. The principal aim of the conference was to discuss the current status of rapidly developing subjects related to primitive forms. In particular, Fukaya category, Gromov-Witten and FJRW invariants, mathematical formulation of Landau-Ginzburg models, and mirror symmetry were discussed. The conference had three introductory courses by experts, and 12 lectures on more advanced topics. The present volume contains two survarticles and 11 research articles based on them. Thus the volume is recommended both to researchers who are already experts in the subjects, and also to graduate students who are interested in and want to start study the subjects.Published by Mathematical Society of Japan and distributed by World Scientific Publishing Co. for all markets except North America