Abstract: The paper aims to understand the effect of weed control and scarification on plantations of Tectona grandis and their undergrowth vegetation. A trial of weed control and scarification on a 2-year-old plantation of Tectona grandis was carried out with treatments of weed control by ‘totally cutting’ (TC) and ‘totally spuding’ (TS), and with treatment of land scarification. The results showed that there were significantly different effects on trees growth and their undergrowth by different treatments: (1) comparing with the treatment of TS, under the treatment of TC, the growth the trees height and DBH decreased by 39.2% and 39.5%, respectively; the average height, coverage and biomass for shrub increased by 32.6%, 76.2% and 184.0%, respectively, and that of herb increased by 36.8%, 5.8% and 39.3%, respectively, but the species of undergrowth shrub and herb decreased by 16.7% and 50.0%, respectively; (2) under treatment of land scarification, the growth of tree height and DBH increased by 13.5% and 11.0% respectively, and the treatment effect on the undergrowth shrub and herb was significant but weaker than that by treatment of weed control; (3) there was significantly negative correlation between the growth of teak tree and the coverage of herb.