To increase the quality of R,R-2,3-Butanediol using inulin extract from Jerusalem artichoke tubers by Paenibacillus polymyxa ZJ-9 and decrease the costs of production,the fermentation conditions including cultural temperature, initial pH,inoculum concentration and agitation speed were optimized.The optimal conditions were confirmed as follows;cultural temperature 30℃,the optimization initial pH 6.0,inoculum concentration 8%(v/v).A two-stage agitation speed control strategy was proposed based on analyzing the microbiol physiological characteristics under different agitation speeds.During the first 24 h,agitation speed was controlled at 240 r/min to obtain high specific cell growth rate for cell growth,subsequently agitation speed was controlled at 160 r/min to maintain high specific R,R-2,3-BD formation rate for high R,R-2,3-BD accumulation.The concentration of the obtained R,R-2,3-BD was 27.83 g/L under this optimal conditions,increase 10.15%than that before optimization.