Pot experiment of continuous planting was carried out for researching potassium biological exhaustion in the lateritic red soil. The results indicate that the biomass of exhaustion treatment rapidly decreased, and soil potassium supply level fall suddenly to the lowest value. It shows that lateritic red soil has weak patience ability to potassium exhaustion, which was related with slow-release available potassium. The results also indicate that the opposite effect of exhausting potassium in the lateritic red soil was very larger than that of rice soil, so it is more urgent to replenish potassium for the former.