The first Seasonal Institute of the Mathematical Society of Japan (MSJ-SI) "Probabilistic Approach to Geometry" was held at Kyoto University, Japan, on 28th July 2008 8th August, 2008. The conference aimed to make interactions between Geometry and Probability Theory and seek for new directions of those research areas. This volume contains the proceedings, selected research articles based on the talks, including survey articles on random groups, rough paths, and heat kernels by the survey lecturers in the conference. The readers will benefit of exploring in this developing research area.