江苏省农业科技自主创新资金[cx(13)2036,cx(12)2035], 江苏高校优势学科建设工程一期项目(yx11500113), 国家农业科技成果转化项目（2011G2B100002）和苏州市农业支撑项目（SN201134）共同资助。
The content of flavonoids in silkworm and its silk was determined using NaNO2-Al(NO3)3- NaOH colorimetry. The results showed that?the flavonoid content in cocoon layers?of green silkworm?variety was five times higher than that in yellow and purple?fluorescent?color?silkworms?and no difference in flavonoid?content was observed in ?cocoon layers? of yellow and purple silkworm varieties. The content of flavonoids in cocoon pupas of green cocoon variety was equivalent to that of purple?fluorescent?color silkworm, but was 1.3 times higher than that in cocoon pupas of the yellow fluorescent?color?silkworm. The content of flavonoids in three varieties of silkworm pupasare was significantly higher than that in cocoon layers.