Ten popular clones were evaluated for growth, latex flow characters, yield and brown bast incidence. Clones differed for initial rate of flow, duration of flow, plugging index, dry rubber content, girth, total volume of latex and dry rubber yield. Girth increment on tapping and incidence of brown bast were not statistically significant. Brown bast incidence was positively correlated with total volume of latex and dry rubber yield. Positive relationships of this trait with initial rate of flow, duration of flow and dry ruber content and its negative relationships with girth increment on tapping and plugging index were not significant. It was indicated that high latex volumea at the initial years of tapping contributed to occurrence of brown bast during subsequent years. Among medium to low yielding clones more interference of other factors was apparent.