During long-term use, the clay checker bricks for regenerators of coke ovens on gas side react with the impurities containing Fe and K2O, causing foaming, softening and deformation, which is not only related with the impurity content and properties of the clay checker bricks, but also related with the type and the composition of the dust in the gas. After long term use, the clay checker bricks of coke ovens on air side have relative lower impurities containing Fe and K2O. The inferior clay checker bricks, with high impurity content and high porosity, are easy to pulverize and deteriorate due to the oxidation reduction reaction with the iron oxide and the gas. The gas quality shall be concerned for long service life of the coke oven regenerators.