Abstract: Effects of carbon sources, nitrogen sources, the loading of yeast extract and nutrient salt on pectinase synthesis from Trichoderma reesei Rut C30 were studied under liquid shakeflask fermentation conditions, and the enzymatic properties were also tested. The results showed that the boiled orange peel (BOP) was selected as the optimum carbon source for pectinase synthesis based on technoeconomic analysis, in which only pectinase was selectively synthesized and secreted, but barely cellulase and trace xylanase came together. Adding 1.0 g/L peptone to Mandels salt was suitable nutrient medium for its pectinase synthesis. After culture for 48 h in the medium containing 12.5 g/L BOP, T. reesei produced the maximum pectinase activity of 32.6 μmol/(min〖DK〗·mL), while the cellulase activity and xylanase activity were restricted within narrow limits of 0.18, 0.63 μmol/(min〖DK〗·mL), respectively, which reached the higher level according to data. The optimum pH value and temperature were 6.0 and 50 ℃, respectively, under this conditions the enzymatic hydrolysis yield reached 80.3 % after 50 h in 10 g/L commodity pectin solution at pectinase loading of 16 μmol/(min〖DK〗·g). According to detection with high performance anion exchange chromatography, in this enzymatic hydrolysate the main end product was monomers other than oligomers of galacturonic acid, and 82.5 % of pectin was converted into monogalacouronic acid.