The wild yeast strain isolated from the continuous crystallization of L-glutamic acid production was preliminary identified and the possible approaches preventing its contamination were consequently investigated in this study.The results suggested that this wild yeast belongs to Candida and it could assimilate and utilize L-glutamic acid for its proliferation,causing the decrease of glutamic in the fermentation broth.Through analysis of the wild yeast's growth-characteristics,it could be concluded that the growth of the yeast almost ceased when the temperature was above 50℃ and could also be inhibited to some extent during the decrease of the pH to the isoelectric point 3.22.Considering the characteristics of the continuous crystallization,the reduction of residence time to avoid contamination was also investigated.Experimental results showed that when the residence time was adjusted to below 9.12h,the wild yeast could be diluted and washed out from the crystallizer.This operation reduces the loss of the main product of glutamic acid during the extraction process.