The gas resistance characteristics in a heat storage packed ball bed was studied by cold state experiments, the effects of gas velocity, diameter of packed balls, height of packed bed and voidage on pressure drop in the bed were examined, and two coefficients in revised Ergun formula were drawn out. The results show that the gas resistance loss of packed bed rises with the increase of gas velocity, and they have a quadratic relationship. With regression analysis on the resistance coefficient, two coefficients in revised Ergun formula are obtained, f1=331.9, f2=1.402, respectively. The calculated unit pressure drop values based on the revised resistance coefficients agree well with the experimental values.