Scent of the flower is one of the plant adaptations that play an essential role in the reproductive processes. Floral scent of many crops attracts insect and animal pollinators and has economic value in guaranteeing plant yield and quality. The emitting time of flavor differs depending on plant species. Most of daytime scent emission flowers are colorful while the nighttime flowers are less in color. Typically, volatiles emitted from the flowers are the mixture of many compounds (Pichersky and Dudareva, 2007). In Thailand, there are more than 264 species of Thai aromatic plants from 72 families and Karawek (Artabotrys siamensis Miq.) is one of 17 fragrant species in Annonaceae (Chatpaisam et al., 2009). The nature blooming Karawek flower noticeably emits foavors from late afternoon to 8 pm.