The aquaculture industry of the world has been facing serious problem due to microbial diseases. The present study was carried out to know the gut microflora of two commercially important crabs, P. pelagicus and P. sanguinolentus for a period of one year from December 2008 to November 2009. The cosumers are eating these crabs without knowing the bacerial contamination. So in this study an attempt wss made to inventigate the bacteriel contamination of crabs in different localities. This information is very useful for tne consumers.