The formation of the diverse pollination systems in Papilionoideae is greatly dependent on the relationships between species richness and their functional groups of pollinators. The floral morphology in Papilionoideae plants is complex. The flowers of most taxa of Papilionoideae have a full complement of organs: pentamerous alternating whorls of sepals, petals, two stamen whorls and a single carpel. The floret has a median sagittal sepal, a bigger vexillum on the outside, and two wings close to the vexillum that parcel two keels of contention. The ten stamens are usually united into two groups (mainly 9+1, few 5+5), called diadelphous stamens. In this paper, we reviewed floral syndrome, functional groups of pollinators, rewards and pollination system in Papilionoideae. Particularly, floral morphology and chemical compositions and their relationships with evolution of pollination systems and mechanism of pollen release were discussed. Pollination system in Papilionoideae plants is mainly bee pollination, with avian pollination, squirrel pollination and bat pollination also present. The pollination system is usually an evolutionary outcome of selection and adaptation between floral morphology and pollinators. The mechanism of pollen release is one of the most important characters that exemplify such interactions between Papilionoideae plants and their pollinators. There are four pollen release mechanisms in Papilionoideae, explosive mechanism, piston mechanism, valvular mechanism and brush mechanism. The selection and adaptation between floral syndrome and the functional groups of pollinators established the pollination system, in which the coordination and adaptation among the components are essential for successful pollination.