Abstract: During the operation of biomass power plant, the transport costs of straw and other transportation fuels account for a large proportion of the cost of the operation of biomass power plant. It is significant to optimize the biomass power plant site. Interval linear programming model was proposed for the biomass power plant site selection. The uncertainty of the information was fully taken into account which included the quantity of biomass, transportation prices and so on. And the number of biomass power plants, optimum site and transportation schemes were obtained with minimum cost, minimum energy consumption and lowest effect on environment. Taking a hypothetical biomass power plant with installed capacity of 45 000 kw for example, the calculation results with the model for the hypothetical example were that: the number of biomass power plant was 1; minimum cost for biomass power plant construction and operation was 0.184 and 0.277 billion respectively; and the coordinate of optimum biomass power plant site was from (258.70, 232.99) to (254.54, 225.89) km. Additional, transportation schemes were also determined, which can provide a scientific basis for decision-makers.