Nepenthes or pitcher plant is one of the most exotic plants in the world. There are 82 species of Nepenthes in the world, and very few studies concerning salinity stress have been carried out. We have found one species of pitcher plant that was exposed to seawater, namely Nepenthes gracilis Korth. Sixty-eight individuals were exposed to seawater and the rest were not. Observing and measuring morphological characters and anatomical characters have been done to these two sample groups in order to reveal the adaptation expression to the salinity stress. Statistical analysis has also been carried out between both groups. Two samples showed that they have significant differences in the size of pitcher and leaf. The ones which were exposed to seawater had smaller pitchers and leaves than others. The exposed seawater pitcher plant also has thicker leaves and palisade than others. Additionally, salinity exposure tended to decrease the stomatal density. The possible reason for this pattern was discussed in this study.