Flowering phenology of plants may be selected to match the seasonality of pollinators, but little attention has been paid for the flowering phenology at community scale. Bumble bees and flies are major pollinators in alpine ecosystems in the northern hemisphere. Bee population highly varies within a season: only overwintered queens are available in early season, and worker bees appear in middle season at high density. Bees tend to select specific flowers more strictly than flies, resulting in a higher competition among bee-flowers. There are no social bees in New Zealand, southern hemisphere, where flies are major pollinators. Therefore, different pattern of flowering penology is expected between northern and southern alpine ecosystems. In Japanese communities, flowering overlap among species was larger in the mid-season, and fly-flowers showed larger overlap than bee-flowers. Bee-flowers showed a bimodal pattern in which early peak corresponded to queen-active period and late peak to worker-active period. In NZ, flowering overlap was large throughout the season, flowering schedule of individual species was loose, and seasonal trend of pollinator activity was less clear. These results suggest that flowering structure of alpine ecosystems highly depend on the lifecycle of pollinators.