Abstract: In order to study genetic diversity of sunflower single cross hybrids through the using principal components analysis, a North Carolina Design I experiment was conducted in a randomized complete block design in three replications at Agricultural and Natural Research Station of Khoy. In 2005, six fertility restorer male lines crossed with 18 cytoplasmic male sterility female lines. Each male line crossed with 3 different female lines to make 2 sets with 9 hybrids in each set. In 2006, Single cross F₁ hybrids were planted for studying genetic diversity. Data were collected from agronomic traits including: flowering initiation, seed filling period, maturity, plant height, head diameter, 1000 seed weight, seed numbers per head, harvest index, oil content, seed yield and oil yield. Survey results showed that three first components explained variability of the all data (77.20%). Traits including seed numbers per head, harvest index, oil content, seed yield and oil yield were the main parts of first component, while second component affected mainly by flowering initiation, maturity and plant height. Seed filling period, head diameter, seed yield and oil yield were the important parts of third component. Totally, first component with high amount of total variance and high correlation with traits including seed yield, oil yield, seed numbers per head, oil content and harvest index could be appropriately useful in grouping and selecting of superior single cross hybrids.