This study was carried out at Plant Production Department, Faculty of Agriculture (Saba Basha), Alexandria University, Egypt during 2015 and 2017 seasons to study the relationship between classer grade, the 3-digit color and trash grades attained from the H.V.I. Three Egyptian cotton varieties i.e., Giza 86, Giza 87 and Giza 90 with different lint cotton grades were used. The obtained results revealed significant correlation coefficients (r =0.76, r =0.75 and r =0.77) between the classer grade (C.G) and instrumental grade (I.G.) for the studied three cottons varieties, respectively. Also, the significant correlation coefficients (r =0.82 and r =0.36) were found between classer grade (C.G) and 3-digit color grade (3-D.C.G.), respectively, for Giza 86, Giza 87 only. The multiple regression model was used to calculate the relative contribution and to predict the classer grade (C.G), the instrumental grade (I.G.) through the H.V.I. fiber properties. The relative contribution percentage of H.V.I. fiber properties to the classer grade, the instrumental grade, the 3-digit color grade and the spinning consistency index was determined. The reflectance degree (Rd%) recorded the highest relative contribution percentage to the classer grade (C.G) of Giza 86 and Giza 90 cotton varieties, while, the fiber bundle strength was the highest contributor to the classer grade of Giza 87.