Abstract: The grain yield is influenced by many complex factors, and it has the characteristics of random and fluctua- lion, so this paper proposed a grain yield prediction model based on grey theory and Markov model. Firstly, the grey re- lational grade was used to screen influencing factor to build the grain yield prediction based on grey model, and then the Markov process was used to modify the forecasting error, making the prediction accuracy increases greatly. hhe simula- lion results show that the proposed algorithm has better prediction accuracy, and the model can satisfy the demand in prediction precision.

Key words: Coal demand, Grey theory, Residual modification, Markvo model