According to Arrhenius Equation, chemical reaction take place slowly when temperature decreases. However, several chemical processes extremely accelerated in ice phase. It is also reported that redox chemical reaction can be enhanced by freezing. For example, Takenaka et. al. reported that the NO₂^- oxidation to NO₃^- in the presence of O₂ which is very slow reaction in aqueous solution was markedly accelerated (appx. 10⁵ times) by freezing Redox transformation of compounds may control the bioavailability, mobility, toxicity, and environmental fate. In this presentation, we will introduce accelerated redox transformation of organic and inorganic pollutants in ice such as Cr(VI)/organic reductants, Cr(VI)/Ar(III), Cr(VI)/H₂O₂, Cr(VI)/NO₂^- and Cr(VI)/phenolic pollutants systems. The detailed experimental conditions and mechanism will be discussed in the presentation. We also discuss about the environmental implication and application of these intrinsic redox transformation in ice on icy environments.