The height and diameter growth performance of 43 Pterocarpus marsupium trees was observed for 13 years at Butwal Sal regeneration site of the Department of Forest Research and Survey of Nepal. The average height growth for the whole study period was 16.87 m and average diameter growth of 22.4 cm. The growth performance at Butwal site was significantly higher compared to that of available nearby growth information. The biomass production by individual tree was recorded during felling operation performed to maintain canopy closure in different treatments. The results suggests that protection against forest fire, grazing and human disturbances favour the natural regeneration if indigenous Sal and its associate species.