THE CURRENT study was conducted to evaluate the rooting behavior of air-layers of Buttonwood (Conocarpus erectus L.) under IBA stimulation and/or inoculation with Bacillus subtilis. Experiment contained two branch lengths (275 and 150 cm) and six treatments of IBA (100, or 200 ppm) and B. subtilis suspension (5 or 10 ml/air-layer from suspension 108 CFU/ml) added individually or in combinations. The best results were obtained by 200 ppm IBA and/or 10 ml B. subtilis resulting in the maximum rooting percentage (100%), the highest number of roots (58.66/layer), the longest root (26.50 cm), large root volume (86.46 cm3/layer), the heaviest fresh and dry roots (82.68 and 13.50 g/layer, respectively) and maximum percentage of layers showing secondary roots (100%). These results were correlated with highest total carbohydrates content (28.40%) and total phenolic compounds (52.41 mg Gallic acid equivalent/g DW). The interaction effects indicated that the superior combined treatment was occurred by shoot length of 150 cm supplied with 200 ppm IBA + B. subtilis.