Abstract: The sericulture ecosystem of Hang-Jia-Hu district in Zhejiang Province, the most important district of silk production in that province, is now seriously polluted by fluoride since 1982. Based on our work several years ago,we recognized that the pollution source was the widely distributed brickkilns and suggested that the atmospheric fluoride concentration should be below 1.2μg/dm²·d in silkworm keeping areas and fluoride Concentration in mulberry leaves should not exceed 30 mg/kg- the safe concentration criteria for spring: silkworm.Four questions were discussed in this paper: the general idea, the control of fluoride pollution, the environmental standard of fluoride concentration, the phases of fluoride in brickkilns exbaust gas. A specific fluoride concentration standard should be defined in the silkworm keeping areas.