Forage production and quality, two crucial ecosystem functions of grasslands, often demonstrate a trade-off and are significantly affected by both grassland community characteristics and environmental factors. However, whether and how these factors influence their trade-off and forage quality storage remains unknown, particularly at regional scale. To explore the effects of plant species richness, plant community composition, climate and soil nutrients on forage production-quality trade-off and forage quality storage, we conducted an experiment across 45 sites of natural alpine meadows on the eastern Qinghai-Tibet Plateau. The results showed that there were significant negative correlations between forage production and quality in overall and forb-dominated grasslands, but not in graminoid-dominated grasslands. Increasing plant species richness decreased forage production but increased quality, aggravated their trade-off, and decreased forage quality storage. Conversely, more graminoids in community increased forage production but decreased quality, broke their trade-off, and increased forage quality storage. Forage production was strongly influenced by climate variables of current year. However, forage quality was affected by most climate variables, and generally decreased with increasing precipitation/temperature. Interestingly, only mean growing season precipitation affected forage production-quality relationship, with high level breaking their trade-off, while it did not change quality storage. In addition, the responses of forage production and quality storage to climate variables were not completely consistent. Increasing soil nutrients increased forage production and crude protein content, did not change forage production-quality trade-off, but increased forage quality storage. These findings advance our understanding of the dynamics of forage production-quality relationship and forage quality storage, and provide theoretical support for the management of alpine grasslands on the Qinghai-Tibet Plateau.