At a spatial scale, the diversity of butterflies varies with numerous factors including the availability of the host plant species. In parity with this proposition, the correspondence of diversity of butterfly and plant in the background of the urban-rural gradient was evaluated using Kolkata, India, as a model study area. The results reveal significant positive correlation between the diversity of butterflies and the plants, with the different values for the suburban, rural, and urban areas. Identification of the butterfly loads for the plants in the respective areas can be useful in enhancing the conservation of the butterflies through enhanced plantation of the concerned plant species. Alternatively, the disclosure of the generalist and specialist pattern of the plant species preference by the butterflies may be useful in enhancing the population of the respective species in the concerned areas. The conservation strategy for butterfly species may be refined through the use of both or any one of the quantitative assessment of the butterfly-plant links in the urban-rural gradient in Kolkata, India, and similar places in the world. © 2019 Swarnali Mukherjee et al., published by Sciendo 2019.