This research aimed to improve the grading system for Lao teak logs. The methodology used the guidelines from VALTIP2 project development, with parameters used to identify plantation teak log quality such as the proportion of hardwood, bend, pipe, knots, decay, end splitting, insect hole, wane, and metal objects. Out of 90 teak logs, 18 teak logs were in grade A, 27 teak logs in grade B, and 45 teak logs was grade C. The proportions of hardwood and knot defects were significant at p<0.05. Logs in grade A had no defects and teak quality depend on silviculture management, log grade A without criteria needs to include more defects such as swelling, routing, and termites because these three defects occurred often in teak logs. The Lao government has approved rules for log grading for native species in which there are four criteria log bend, log routing, swelling, and log decay and only a short time is required for log analysis. This research into a different method using Lao government criteria resulted in a more complex method and took a long time because the plantation teak logs were small and had many defects.
Keywords: Teak log, grading, measurement and improving