Among the major issues in the implementation of REDD+ activities is leakage or displacement‟ resulting from activity shifting associated with the process. This study aimed at assessing potential leakage in terms of carbon stock and emission difference by degradation in REDD+ pilot site and areas around REDD+ pilot project in Kilosa. Data were collected from 84 rectangular plots measuring 20×10m established within the REDD+ pilot site and around REDD+ pilot sites. The numbers of stumps, stump diameter, diameter at breast height (DBH) for trees ≥5cm diameter and species local and botanical names were recorded. The above ground carbon stocks were estimated to be 31.5 tCha -1 in the REDD+ pilot site and 3 tCha -1 around REDD+ pilot sites. The genera Brachystegia contributed the highest amount in both sites with 70% of total above ground carbon in REDD+ pilot site and 55% around REDD+ pilot site. Areas around the REDD+ pilot site had higher stump density of 70 stumps ha -1 than those in the REDD+ pilot site with 12 stumps ha -1 of which majority were Brachystegia microphylla and Brachystegia boehmii. The estimated carbon loss was 1.17 tCha -1 (4.29 tCO 2 e ha -1 ) in REDD+ pilot site and 1.92 tCha -1 (7.05 tCO 2 e ha -1 ) around the REDD+ pilot sites. This is an indication of shifts in utilization resulting from the implementation of REDD+ activity in Kilosa. Such anomalies should be addressed before one can judge the success of the REDD+ project in the area. Key words: Carbon emission, degradation, leakage, REDD+ pilot site