To study mechanisms affecting particulate matter production from forest fires, a combustion chamber system was developed. This closed system was used primarily for producing cylindrical laminar diffusion flames by burning alpha-pinene under controlled conditions. The independent variables for the tests were type and supply rate of fuel, and oxygen index, temperature, and supply rate of primary diffusion air. The emission factors for particulate matter (EFp) were determined by filtering and weighing the mass of particulate matter produced and dividing that value by the mass of fuel consumed. The EFp values were found to be a function of flame volume for the cylindrical laminar diffusion flames. Increasing the air supply rate increased the EFp for a constant .fuel supply rate. The EFp increased proportionally when the fuel supply rate was increased. Generally speaking, the EFp decreased as the oxygen content of the fuel increased. This seems to agree with observations for composite forest fuel specimens.