Present study is intended to observe the complicated mouth organs of the weevils in the normal position without dissection mostly by SEM and partly under the binocular microscope, and to infer their possible mechanisms of feeding and relationship to classification. Present study treats the family Rhynchophoridae and the results obtained are as follows. This family is unique among the Curculionoidea by the prementum, which is deeply retracted into the ental side of the oral cavity. The mandibles are of adducent type and the maxillae move in a vertical plane. The labial palpi are typically three-segmented, but reduced to one-segment in many species.