Predicting how warming-induced shifts in plant species-specific phenology affect species dominance remains challenging. Here, we investigated the effects of experimental warming on plant species-specific phenology and dominance as well as their relations in an alpine meadow on the Tibetan Plateau. Warming significantly advanced phenological firsts (leaf out and first flower dates) for most species, while having variable effects on phenological lasts (leaf senescence and last flower) and full phenological periods (growing season and flower duration). Experimental warming reduced community evenness and differentially impacted the species-specific dominance. Specifically, warming-induced shifts in phenological lasts and full phenological periods, rather than the single phenological firsts, are associated with changes in species dominance. Species with lengthened full phenological periods under warming increased their dominance. Our results advance our understanding of how altered species-specific phenophases can be related to changes in community structure in response to climate change.