The immature stages of butterfly, the common mormon-Papilio polytes Linnaeus (Lepidoptera: Papilionidae) were studied at Solan, Himachal Pradesh. This butterfly is an active flier and prefers mostly gardens and human habitations. The larvae are polyphagous and observed on three plants belonging to the family Rutaceae viz., Citrus aurantifolia (Cristm.) Swingle, Murraya koenigii (L.) Sprengel and Zanthoxylum alatum Roxb. Some observations on its biology, and nectar host plants are included.