Provided is a definition method of herbaceous plants for handling global climate changes. The method is used for screening out the herbaceous plants which are high in carbon sequestration efficiency and have a high economic value, controlling stony desertification and desertification, reducing beach erosion and water and soil loss, increasing the total carbon storage amount and total biomass amount of an earth ecological system, developing new climate economy and achieving a zero-carbon development pattern. The method includes the steps of (1), determining a definition range and selecting theherbaceous plants suitable for development of agriculture, forestry, husbandry, by-products and fishery within the definition range; (2), determining each biological index of the herbaceous plants which are high in carbon sequestration efficiency and capable of governing stony desertification, desertification, beach erosion and water and soil loss; (3), randomly selecting 10 colonies and determining excellent plants in the colonies; (4), determining a coverage degree of the excellent plants in the colonies and conducting primary classification according to the indexes in step (2); (5), determining the biomass and propagation capability of the excellent plants in the selected colonies and conducting secondary classification according to the indexes in step (2); (6), completing definition when the accuracy rate is greater than 90%.