Thepresent investigations was carried out to determineprediction equation and the relative contribution of five fiber properties toestimateyarn strength, neps and evenness on count 80,100 and 120 for Extra-long (extra fine) and Extra-long stableof Egyptian cotton varieties under combed ring spinning systems. The full model regression and stepwise multiple linear regression model wereused to satisfy the target of work. The results of the supposed models of regression differed according to theExtra-long (extra fine) and extra-longof Egyptian cotton varieties and also the applyingyarn counts. Generally, under combed ring spinning system, Upper half mean Length was themost effective fiber properties topredict yarn properties for theExtra-longExtra fine, Extra-long stableon counts 80 100 and 120 while, fiber strength andmicronairewere themost important fiber traits contributing toyarn properties using theExtra-long (extra fine) stableon count 120 in Egyptian cotton varieties. The Fiber diameterwas thegreatest influenceon the studied yarn properties for theExtra-long stapleon count 120while, FiberDiameterranked the first in fiber properties that used topredict theyarn strength on count8os for theExtra-long stable in Egyptian cotton varieties. All the supposed models of regression were significant and reflected largepart of thevariation of studied yarn properties expressed as high values of R² and near values of the corresponding adjusted R² indicating thevalidity and goodness of fit for these models.