The amount of surface run-off and soil erosion on a field of young tea with a ten per cent slope were measured under four soil management treatments (manual weeding, herbicide weeding, oats planted between rows of tea and grass mulch) for a period of three years. The study was made on a typical Kericho District tea soil derived from a massive sheet-flow of phonolite lava. The run-off and soil erosion were greatest in the absence of erosion control measure (manual weeding and herbicide weeding). Mulching gave the lowest run-off and least soil erosion. In general, the amounts of run-off and soil erosion were both greatest in the first year when the ground cover provided by the lea canopy was between 1 and 30 per cent, but they were reduced to very small amounts in the third year when the ground cover was more than 60 per cent.