Abstract: Microsopic greyness of bio-issues is widely applied in the field of biological medicine.In this study, using MIAS-300 (Image Analyzer System),we explored the factors inflluencing the greynees of biological issues.Teh results of our study indict that all the microsopic light intensity, Gain values and threshold values influence the measurement results and the quantitative analysis of chemical components of biological samples directly. Therefore, we suggest that the researchers attach much more importance to there influencing factors in their greyness of bio-issues.