This study was carried out in the Laboratories of Cotton Grade Section, Cotton Research Institute, Agricultural Research center, Giza, Egypt and spinning unit of Industrial Menia EL- Kameh, EL- Sharkia Governorate, Egypt in 2016 and 2017 seasons, to investigate the relationships between fiber properties and lea product, single yarn strengths and unevenness at 40's and 60's yarn count at 3.6 twisting index for Giza 86,Giza90 and Giza95 cotton varieties, with using FQI, SCI, PDI and MI_AHP as mathematical models. The technological values were estimated by four models correlated positively with high significant and each of lea product and single yarn strengths, in both seasons. On the contrary, this correlation was negative with the regular percentage for Giza 86 and Giza 95 varieties, SFC, UHML, FS and the Mic value had the highest contribution toward yarn quality properties at 40's and 60's Y.C for the studied varieties.