In recent years, the risk of new weeds entering Japan from overseas has increased due to climate change and the globalization of the movement of people and goods. It demands a lot of labor and cost to control the many exotic weeds spread in the fields. Therefore, it is an urgent task to develop technology to prevent invasion, establishment, and expansion of distribution of high-risk weeds, which would cause great damage if spread. It is also urgent to develop effective control methods for weeds that are difficult to control, such as weedy rice and perennial weeds, in order to spread and expand direct seeding rice cultivation that contributes to reducing the production cost of paddy rice. Thus, in the division of weed control research, we are working on the prevention of noxious weed invasion through development of weed risk assessment of non-invasive alien plants and a weed diagnosis and identification system using AI, and also on development of integrated weed management for difficult-to-control weeds.