The result from this study showed that in naturallyfermented sour pickled mustard green, the fermentationwas inconsistent indicated by increment in pH duringfermentation and the higher final pH. Addition of the LABstarter culture was shown to help improving the consistencyof the fermentation, especially at the high level ofinoculum. Analysis of the LAB diversity revealedsuccession of the LAB species from Weissella spp. to Lb.plantarum in naturally fermented batch and from Weissellaspp. to Lb. fermentum in starter culture-added batches.Therefore, it is suggested that Lb. fermentum may play animportant role in the mustard green fermentation. Thisknowledge can be used in development of new starterculture that is more efficient in the pickled mustard greenindustries.