In order to improve the forecasting precision of the electric-power demand, a Grey-Markov model for forecasting the electric-power demand is established. The model combines the advantages of both Grcy forccasting mcthod and Markov chains forecasting method, overcomes the influence of random fluctuation data on forecasting precision and widens the application scope of the Grey forecasting. An application example is conducted to evaluate the Grey-Markov model, which shows that the precision of the Grey-Markov model is better than that of Grcy model in forccasting thc electric-power demand