Abstract: SDS-PAGE is a very powerful and effective method in protein analysis.Sometimes it is difficult to locate the sample wells and spaces between them because the isolation gel concentration gel and electrophoresis buffer are transparent and colorless and they could only be identified and distinguished by light refraction in the process of sample loading.This paper introduces a new method in which dye is added into the concentration gel to make it different by resulting in a dual-color phases of SDS-PAGE gel.With this method, it is very easy to see the loading wells by eyes.The process of sample loading can be finished in an accurate and efficient way and electrophoresis quality can also be improved by visible color border among phases between wells and gel.