Traditional Antheraea pernyi silkworm cocoon is tawny color. The white Antheraea pernyi silkworm cocoons studied here by IR and UV are new breeds of recent breeding. We discovered that the main body of the first grade structure of silk protein in the new white is as same as the one in the traditional tawny Antheraea pernyi silkworm cocoon, yet there are small quantities of cross-linked polymer of gentisic acid and silk protein in the white silkworm cocoons. In spite of the least surviving quantity of the polymer, the white silkworm cocoons are most white and its white color is similar to white Bombyx mori silkworm cocoon.