Abstract: Objective:Mixed strains was used to ferment roxburghii rose pomace for improving the content of soluble dietary fiber (SDF) in the pomace dietary fiber.It would provides a reference for the industrialized production and product development of SDF in roxburghii rose pomace.Methods:Based on single-factor experiments,the optimum process was optimized on the basis of the Box-Behnken test design using dietary fiber yields as response values.Results:The optimum conditions for preparing the soluble dietary fiber of roxburghii rose pomace were as follows:The ratio of Lactobacillus acidophilus,Lactobacillus pentosus and Saccharomyces cerevisiae were 1:2:1.The ratio of material to liquid was 1:5.The amount of inoculum was 10%.The temperature and time of fermentation were 30℃ and 52 h, respectively.Under these conditions,the yield of SDF reached 11.590%,which was 76.53% higher than that of original fruit pomace.The total dietary fiber obtained by the fermentation method had higher swelling force,water holding capacity and oil holding capacity than the original pomace. Conclusion:Microbial fermentation preparation of dietary fiber can effectively improve its quality indicators.That's a simple and high-quality method of dietary fiber.