For the production of theobromine from caffeine, 5 strains of bacteria capable of producing theobromine were isolated from soil. Among them, the strain CT-017 showed the best ability of producing theobromine, and was partially identified as a Pseudomonas sp. For the production of theobromine, fructose was the most effective carbon source at an optimum concentration of 5 g/ℓ. The most effective nitrogen source was 5 g/ℓ of beef extracts. And 0.02 g/ℓ of Fe^(2+), 1.0 g/ℓ of threonine were effective for the production of theobromine. The optimum temperature and initial pH were 28℃ and 6.5, respectively. After 23 hr cultivation, 7.98 g/ℓ of theobromine was produced from 15 g/ℓ of caffeine which corresponds to a conversion yield of 53.2%.