Abiotic stress–tolerant genetically modified (GM) plants are expected to be next-generation plants that will bring stable yields to cope with future population growth and climate changes due to global warming. However, tolerance to abiotic stress may affect the fitness and possibilities to invade natural environments more than herbicide-tolerance and insect resistance, which have already been approved; therefore, it has been pointed out that the modified plants may have a larger niche than the host plants. Although methods of environmental impact assessments for abiotic stress–tolerant GM plants have been discussed in international meetings, a clear answer has not been reached. These new GM crops have been experimentally grown in fields in the U.S., Canada, Australia, EU and Japan. Our study on the legal framework used when these countries assessed the safety of the plants, together with information about the agricultural background, showed that the countries used the current assessment system without any changes, or expanded the interpretation of the current assessment system or added new methods to the system for the environmental impact assessments of abiotic stress-tolerant GM plants. A new method of assessment involving population dynamic models has been proposed. It may be possible to construct a uniform world standard method based on this proposal by using true abiotic stress&amp;#8722;tolerant GM plants.