Foraging patterns of bumblebees rely on the spatiotemporal variations in floral resource conditions. We compared resource use patterns of bumblebees between urban and montane forests. The urban forest is located nearby residential area where various garden species grow at high density. Bumblebees of the urban site often foraged outside the forest. Six bee species inhabited the urban site, while five in the montane site, and four species were common. Two species of the urban site were specialized in open habitat. A longer flowering season in the urban site made bumblebee lifecycle longer than that in the montane site. The average number of plant species visited by each bee species was 1-3 spp. per day (max. 12) in the urbane site and 1-2 spp. (max. 4) in the montane site. Of pollen grains deposited on bee’s body, pollen species occupied >10% were classified as major foraging species. Identified pollen species in each bee increased up to 13 spp. as the available number of blooming species increased. However, the number of major foraging species remained around 1-3 spp., which was almost the same number as the blooming species in which bee visitation was observed. Thus, individual bees did not increase the major foraging species even in the urban site provably because of the intense floral constancy. However, they increased the number of minor foraging species.