Abstract: It has been found that sodium pyrosulfite sometimes was added into immersed water for water bamboo based on the survey results from farm producer and market. The immersion test for water bamboo with sodium pyrosulfite was conducted in this study. The results showed that the immersion with sodium pyrosulfite could slow down the occurrence of rust on the surface of water bamboo， and increased the whiteness and brightness of water bamboo. The residues of SO2 in water bamboo without shell were relatively high after soaking 1\|4 hours， and then gradually declined. The concentration of SO2 in water bamboo with shell reached the peak at 2 days after soaking and then declined. Generally， the risk of SO2 via dietary exposure was acceptable. It wasnt suggested that consumers buy the water bamboo without shell， or it shouldnt be consumed until 4 hours after purchased from market.

Key words: water bamboo, sodium pyrosulfite, immersion test, risk assessment