Abstract: Background and Objective: Plants have different response to heavy metals and some plants have ability to absorb and reduce heavy metal contaminant such as lead and mercury from the environment. The objective of this experiment was to analyze the morphological, anatomical and physiological responses of four non-edible oil producing plants to mercuric (Hg) treatment in hydroponic culture. Materials and Methods: About 3 months old of 4 species (Melia azedarach, Ricinus communis, Jatropha curcas and Reutealis trisperma) were grown in water culture using Hoagland solution treated with mercuric nitrate [Hg(NO3)2] of 0, 0.5, 1, 2 and 3 mM for 21 days. The observation was made to see morphological, anatomical and physiological responses of the plants to Hg treatments. Results: Mercury (Hg) decreased dramatically the growth rate of the plants including plant height, number of leaves and the dry weight of shoot as well as roots, even though there was variation among the species. Mercuric treatment also induced lipid peroxidation which was marked by the increase of malondialdehyde content (MDA), while it caused dramatic decrease of total chlorophyll content. The increase of Hg accumulation on plant tissue caused the alteration of anatomy structure like decreasing the thickness of upper layer of epidermis, palisade and spongy mesophyll cell, which at the end it caused the decrease of leaf thickness. Conclusion: Based on morphological, anatomical and physiological changes, R. trisperma was the most tolerant to mercuric treatments, followed by M. azedarach, while R. communis and J. curcas were categorized as the less tolerant to Hg treatments compared to the other two.