Abstract: To assess the effects of biochar application on the conversion of soil phosphorus and the numbers of phosphate solubilizing bacteria (PSB) in acid red soil, a eight week PSB inoculation microcosm incubation experiment was performed using soil from tea plantation, and biochar adding treatment of 0%, 1% and 3% (w /w ) were conducted. The results showed that: the numbers of PSB decreased rapidly after inoculation, the application of biochar significantly increased the numbers of PSB in tea plantation, which was 10.5-15.25 times as much as that of control treatment. In addition, the application of biochar increased soil pH value,available P (Bray-P) content, and alkaline phosphatase enzyme activities. Correlation analysis showed that: there were positive correlations between numbers of PSB and organic matter content, total nitrogen, total phosphorus, pH value and alkaline phosphatase enzyme activities; and a negative correlation between numbers of PSB and acid phosphatase enzyme activities. In summary, compared with control treatment, the application of biochar increased the numbers of PSB and activated soil P in red soil tea plantation.