Abstract: [Objective] Using quinoa puree as the main raw material,and Streptococcus salivarius subsp. thermophilus and Lactobacillus delbrueckii subsp. bulgaricus were simultaneously used to ferment quinoa for the preparation of quinoa yogurt,and its basic properties and antioxidant activities were investigated. [Method] Based on the single-factor experiments（fermentation time,fermentation temperature,inoculation amount and the addition amount of white granulated sugar）,the optimal fermentation process was established through the response surface experiment. [Result] Fermentation time and fermentation temperature had significant effects on the quality of quinoa yogurt（P<0.01）,the conditions for yogurt fermentation were as follows：the fermentation time was 8.3 h,the fermentation temperature was 43.4 ℃,the inoculation amount was 1.2%,the sugar content was 4.2%,the physicochemical indicators of the quinoa yogurt obtained under this condition were good,all the microorganisms met standards,the free radical scavenging rate of DPPH was（73.41±0.91）%,and the sensory evaluation score was （88.33±1.21）points. [Conclusion] By fermenting quinoa as raw material,a quinoa yogurt with high nutritional value and antioxidant capacity could be obtained.

Key words: quinoa, quinoa yogurt, process optimization, sensory evaluation, antioxidant activity