Abstract:The Interference problem in heterogeneous network is serious, this paper proposes a femtocell spectrum allocation algorithm in load forecasting based grouping method.In this algorithm stastics of historical load in both femtocells and macrocells were used to get and optimize the future load informations.Then all the femtocells were clustered by using the future load informations,each cluser allocates spectrum independently.By this way, interference of the same layer can be reduced effectively.The simulation datas show that due to the adoption of the load forecasting based femtocell clustering spectrum allocation algorithm, the SINR and throughput of system were highly improved,the interference problem was effectively solved.