The effect of amount of sand on gasification performance, such as lower heat value of product gas and amounts of oil and char formed, was studied by using a reactor of 57.5 mm diameter and 600 mm length. In this partial combustion gasification,a smaller degree of partial combustion is desirable for better utilization of heat of combustion, Such partial combustion was realized with relatively large amounts of sand. By considering this fact, and the observed behavior of the lean phase fluidized bed in a cold model experiment, an incipient bed height/column diameter ratio of 1.2 to 1.7 may be advisable for better gasification performance.