The grape leafhopper, Arboridia kermanshah Dlabola (Homoptera, Cicadellidae), is an economically important pest of most vineyards in Isfahan . Effects of some irrigation regims and grape cultivar on seasonal population changes and damage of A. kermanshah were studied in IUT vineyard in 2005-2006. Effect of water stress was assessed on five local grape cultivars including Shahani, White Rishbaba, Askari, Black Rishbaba and White Yaghotii in a complete randomized block in three replications. Two drip irrigation regims, one normal irrigation (100 liter/ tree/ week) and the other one minimum irrigation (100 liter/ tree/ two weeks) were used. Host plant preference and seasonal changes of the pest without effect of water stress were determined on nine cultivars including White Yaghotii, Black Yaghotii, Askari, Rishbaba, Khalili, Rotabi, Red Keshmeshi, Black and White Keshmeshi. To study seasonal population changes of the pest, nonparasitized and parasitized eggs were counted weekly by clipping three leaves from different strata of vine canopy as sample unite, in each plot. Adults and nymphs were assessed by weekly sampling using vacuum set (D-vac). Percentage of damage measured with Leaf Area Meter. Oviposition preference of A. kermanshah was studied by choice and no-choice experiments and measuring hair density of leaves. In choice experiment supplied cuttings of nine grape cultivars were planted pairly in pots as 36 compositions with 4 replications. When cuttings had 40 cm length and 6-10 expanded leaves, 10 adult males and 15 adult females were released in netted cages by 50 × 50 cm dimensions. In no- choice experiment, 5 males and 10 females were released in leaf cages by 15 × 15 cm. In both experiments, one week after release, all leaves were picked and eggs were counted in laboratory. To study performance of different nymphal instars on nine mentioned varieties, leaf cages mounted on leaves with 1-2 eggs in 3 replications and were monitored daily until appearance of adults. Maximum number of adults and nymphs were observed on White Yaghotii, minimum number of adults and damage percentage were on Black Yaghotii. White Kheshmeshi, Red Kheshmeshi and Black Yaghotii cultivars had the lowest density of nymphs. The longest period of nymphal development was observed on Black Yaghotii was29.33 ± 0.3 days and the lowest was on White Yaghotii, 26.33 ± 0.9 days. In both expriments, the lowest number of eggs was laid on Black Yaghotii, which had moderate hairs density (0.03- 0.08 hair in mm 2 ) on surface of leaves. In choice experiment, the most ovipositied eggs was observed on White Yaghotii cultivars athwart had highest hairs density (mo