An investigation was conducted in order to determine the tick species of sheep body surface and their seasonal population variations in maraghe province from March 2008 to april 2009. Sampling was done from overally 1200 sheep of both sexes. Collected data were analyzed using SPSS computer software. The results revealed that 266 (22.22%) sheep was infested by hard ticks. the highest percentage of the sheep ticks infestation was observed in june 2008, while lowest percentage was in during February 2008. There was a significant difference (p<0.05) in the tick population of sheep during the seasons and months of the year. Out of 1279 ticks were collected on sheep and were identified as: R.turanicus (48.51%), Hy. anatolicum. anatolicum(15.01%), D.marginatus (11.91%), R.sanguineus (8.22%), Ha.punctata (4.32%), Ha.sulcata (3.66%), Hy.anatoliium. excavatum (3.22%), Hy.marginatum (2.56%), R.bursa (2.53%). the difference of ticks site preference was significantly noticeable. Distribution of ticks over different parts of sheep body surface according to their frequency were as follow respectively:head and meck(63%), under the tail (23%), under armful(10%), groin(4%).(p<0/05).