Abstract: An alkaline pectinase producing strain Lys-3004 was isolated from a decayed apple by combination of plate screening and Congo red staining. Based on morphological characteristics and 16S rDNA amplicon sequencing analysis, strain Lys-3004 was identified as Bacillus sp. The optimum fermentation conditions of pectinase activity were performed by single factor and orthogonal experiment. The results were as follows: glucose 7.0%, soybean meal 1.2%, initial pH of medium 7.0, 180 r/min at 33 ℃, culturing for 96 h. Under the optimum conditions above, the enzyme activity of strain Lys-3004 reached 11 352.5U/mL, which was 3.7 folds higher than that obtained before optimization. Strain Lys-3004 is capable of potential applications for following researches.