If you want to attract butterflies to your garden, you have to choose plants suited to your surroundings and the species you are apt to see in your area. Do you live near woods, an overgrown field, an empty lot, a road?
Different sites attract different species: look carefully at the butterflies that visit your area and identify which plants they prefer. This will help you choose the right plants for attracting these species to your garden. By identifying the different species, you'll also be able to find out about their habits and their needs.
Your garden should include nectar plants for feeding the butterflies, and host plants as sites for laying eggs and food for caterpillars.