This study was carried out at during 2019 and 2020 seasons on the laboratory at Cotton Technology Research Division, Cotton Research Institute, Agricultural Research Center, Giza, Egypt, to investigate the effect of six Egyptian cotton varieties (Giza 92, Giza 96, Giza 86, Giza 94, Giza 95 and Giza 90) and three categories of short fiber content (5.50, 6.75 and 8.25 %) which obtained from three lint cotton grades, i.e. fully good, good and fully good fair respectively, from each cotton variety on fiber and yarn quality measurements under using the new technique of the ring spinning system. Extra long staple as Giza 92 and Giza 96 significantly recorded the maximum upper half mean length (UHML), fiber bundle strength (FBS), lea count strength product at yarn count of 40's (LCSP40), lea count strength product at yarn count of 60's (LCSP60), single yarn strength at yarn count of 40's (SYS40), single yarn strength at yarn count of 60's (SYS60) and yarn evenness at yarn count of 60's (YE60) as well as gave the lowest short fiber index (SFI), fiber elongation percentage (FEP), micronaire value (MIC), trash area (TA) and trash content (TC) in both seasons. The greatest fiber uniformity index (FUI), MIC and fiber maturity (FM) as well as the minimum yarn evenness at yarn count of 40's (YE40) and YE60 in both seasons were obtained from Giza 86 cotton variety. Giza 94 cotton variety recorded the highest fiber brightness degree (Rd) as well as the lowest linear density (LD), fiber yellowness degree (+b), LCSP60 and SYS60 in both seasons. The highest SFI and +b were obtained from Giza 95 cotton variety in both seasons. Giza 90 cotton variety gave the highest FEP, LD, TA, TC and YE40, as well as gave the lowest UHML, FUI, FBS, FM, RD, LCSP40 and SYS40 in both seasons. Increasing short fiber content from 5.50, 6.75 to 8.25 % caused significant increments in SFI, FEP, +b, TA, TC, YE40 and YE60. On the other hand, UHML, FUI, FBS, MIC, FM, LD, Rd, LCSP40, LCSP60, SYS40 and SYS60 were significantly decreased in both seasons. Giza 92 cotton variety at fewest short fiber content (5.50 %) gave the maximum FBS, SYS40 and SYS60, while at highest short fiber content (8.25 %) recorded the minimum MIC and the highest YE60 in both seasons. Giza 96 cotton variety at lowest short fiber content gave the highest UHML, LCSP40 and LCSP60, as well as gave the lowest SFI, FEP, TA and TC in both seasons. The maximum FUI, MIC, FM as well as the lowest YE40 and YE60 in both seasons were produced from Giza 86 cotton variety with lowest short fiber content. The maximum Rd and lowest +b were obtained from Giza 94 cotton variety at lowest short fiber content, while, with the same cotton variety with highest short fiber content recorded the lowest LD, LCSP60 and SYS60 in both seasons. The fibers which obtained from Giza 95 cotton variety with highest short fiber content significantly recorded the greatest SFI and +b in both seasons. The maximum FEP, TA, TC, YE40 as well as the minimum UHML, FUI, FBS, FM, Rd, LCSP40 and SYS40 were obtained from Giza 90 cotton variety when used highest short fiber content, while, under the same cotton variety at lowest short fiber content recorded the highest LD in both seasons. There were significant negative correlation coefficients between (SFI, FEP, +b, TA, TC and YE40) and (UHML, FUI, FBS, MIC, FM, LD, Rd, LCSP40 and SYS40).