The present study was conducted to evaluate some morphological characters of some cowpea genotypes under saline water irrigation in newly reclaimed areas, under North Sinai Governorate (El-Arish) conditions as well as the natural infestation with aphid and its hymenopterous parasitoids. Five cowpea genotypes were used; Creamy, Brahma, Buff, Toshki and Chick (Local cultivar). Creamy genotype surpassed the other genotypes of forage yield as well as seeding yield and their attributes followed by Barahma, Buff, Toshki and lastly the Chick (Local) in 2007 and 2008 seasons. The percentage of infestation caused by aphid nymphs varied from (0.49 to 12.7%), (0.49 to 14.6%), (0.36 to 21.8%), (0.78 to 38.5%) and (1.22 to 4.11%), in the five genotypes, respectively, in the first season (2007). The percentages of infestation varied from (0.11 to 13.8%), (0.79 to 3.59%), (0.52 to 20.7%), (1.55 to 28.9%) and (3.54 to 35.8%), respectively, in the second season (2008). On the other hand, the total percentage of infestation among the five tested genotypes ranged between (0.71 to 10.8%) and (0.67 to 16.1%) in the first and the second season, respectively. The average percentages of parasitism caused by the hymenopterous parasitoids on aphid nymphs were 2 to 4% during the first season 2007 and 4 to 5% during the second season 2008, respectively.