This book constitutes the refereed proceedings of the 18th JSAI International Symposium on Artificial Intelligence, JSAI-isAI 2026, held in Gunma, Japan, during June 7–9, 2026.

The 15 full papers were included in this were carefully reviewed and selected from 46 submissions. They focus on models of legal reasoning, computerized legal education, AI legal problems, use and exploration, the vast business and AI technology fields.