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选择松嫩草地上的3种优势牧草羊草(Leymus chinensis)、碱蒿(Artemisia anethifolia)和全叶马兰(Kalimeris integrifolia) ，通过野外干旱胁迫试验、定点实时观测和隶属函数法，研究3种优势牧草在不同生育期内对不同等级干旱胁迫的响应，探究不同等级干旱胁迫对牧草在不同生育期内形态特性的影响及其抗旱能力。结果表明：在牧草同一生育期内，随干旱胁迫程度加剧，株高、叶长、叶绿素含量和产量受到的影响越大，在特旱程度下，3种牧草生长受干旱胁迫影响最严重；同一干旱胁迫处理下，随着生育期推移，株高、叶长、叶绿素含量和产量受干旱胁迫的影响总体呈减少趋势。3种牧草在其生育期内的抗旱性呈现出一定的规律性，羊草在开花期抗旱能力最强，其次是在返青期；全叶马兰在开花期抗旱能力最强，其次是在返青期，在抽穗期最差；碱蒿在开花期抗旱能力最强，其次是在抽穗期，在返青期最差。本研究结果对松嫩草地3种优势草种在不同生育期内遭受不同程度干旱胁迫时采取不同应急方案具有指导作用，也为培育优良耐旱草种及草地生态系统可持续发展提供了一定的参考。“,”To quantitatively evaluate the effects of different levels of drought stress on the morphological characteristics and drought resistance of three dominant grass species at different growth stages, field drought stress experiments, membership functions, and fixed-point real-time observations were carried out in the Songnen grassland. The results showed that, at the same growth stage, the higher the degree of drought, the greater the influence of drought stress on plant height, leaf length, chlorophyll content, and yield. Consequently, the morphological characteristics of the three types of forage were most seriously affected under extreme drought stress. Under steady drought stress conditions, the plant height, leaf length, chlorophyll content, and yield gradually decreased with growth stage, and the morphological characteristics of all three types of forage were most seriously affected in the turning green stage. When both the growth stage and drought grade were superimposed, a synergistic effect on the morphological characteristics of all three forages was observed. The drought resistance of the forages during their growth periods showed a certain trend. All three showed their strongest responses at the flowering stage. However, while Leymus chinensis and Kalimeris integrifolia had a stronger response to drought stress during the turning green stage than at the heading stage, Artemisia anethifolia showed a higher resistance during the heading stage than at the turning green stage. The results of this study may be used as a guide when planning for contingencies involving drought stress faced by grasses at different growth stages. It may also provide a reference for cultivating excellent drought-tolerant grass species and for the sustainable development of grassland ecosystems.