Abstract: Nondestructive detection of chicken-egg internal quality is necessary for circulating and processing of chicken-eggs. In order to improve the precision in nondestructive detection by optical properties, an optical model was established to find out the relationships among transmittant properties of the whole-egg, the contents inside and the egg shell. Through tests, correlations were obtained between chicken-egg internal index (Haugh Unit) and whole-egg transmittant ratio, egg-shell colour and egg' s geometric parameters. Ways to improve the precision of nondestructive detection by optical properties were preliminarily analyzed.