Abstarct: Hetero-polyanions are anionic mextal oxide clusters with the general formula of [XxMmOy]q- (x≦m) in which M is usually tungsten or molybdenum. Polyoxomextalates of the Keggin-type have been known for over 150 years. Bulk HPA as catalysts have low stability and surface area (1–10 m2/g). To improve these characteristics of the HPAs, they are usually supported on a suitable carrier that not only increases its thermal stability and available surface area but also improves its catalytic activity . Impregnation and adsorption which usually used for supporting HPAs on different carriers also suffers from gradual leaching of HPAs from the surface. So in this work, we have been tried to support HPAs to the surface of zirconia via covalent lixnkage. Amorphous zirconia was prepared by the hydrolysis of zirconium(IV)oxide chloride with dropwise addition of ammonia solution. Then the amorphous zirconia was covalently functionalized with tri-methoxy silyl propyl amine. The phosphomolybdic and silicomolybdic HPAs also were prepared according to the reported procedures in reference and then they were supported on functionalized zirconia. The prepared catalysts were characterized by BET, TGA, UV-Vis spectroscopy, FT-IR spectroscopy, ICP and CHN analysis. Epoxides (oxiranes) are three-membered cyclic ethers that are prepared from alkenes by reaction with different peroxides and peracids. The catalytic epoxidation of alkenes is an important reaction in chemical industry since epoxides are versatile and important intermediates in the synthesis of fine chemicals and pharmaceuticals. The use of heterogenic catalyst could be improved separation process of catalyst which is very important especially for the pharmaceutical materials. In this work we have been used the epoxidation of cyclooctene as a model reaction with prepared catalysts. The various parameters such as type of solvent, type of oxidant, amount of oxidant and amount of catalyst were optimized for this reaction. The progress of these reactions was analyzed using gas chromatography (GC) during 30-180 minutes. The optimum conditions were found carbon tetrachloride as a solvent, 1.12 mmol TBHP as oxidant, and 20 mg catalysts for 0.5 mmol cycloocten at reflux temperature. At these conditions, the supported 12-molybdophosphoric acid reached near complete conversion during 2 hours. But, the supported 12-molybdosilicic acid reached near complete conversion during 3 hours. The experiments also showed that these catalysts could be recovered and reused up to 4 cycles. Heterogeneized heteropolyacids, H3[PMo12O40]/ZrO2 and H4[SiMo12O40]/ ZrO2 were shown to catalyze oil transesterification with ethanol in mild conditions and the product obtained was confirmed by IR analysis.