The effect of bio-fertilizer (Nitrobein) on the infestation of the two Jerusalem artichoke cultivars (Local and Fuseau cultivars) by four arthropods which are Tetranychus urticae Koch, &nista tabad Genn., Aphis gossypiiGlover and Thrips tabaci Lind. during summer seasons of 2002 and 2003 at Barrage Horticultural Research Station was investigated. Nitrobein level of 8 kg/fed. with 75, 50 and 25 % of the recommended rates of nitrogen, phosphorus and potassium (RNPK) were used. The check control treatment was 100 % of the (RNPK) nitrogen (40 kg N/fed.), phosphorus (22.5 kg P205/fed.) and potassium (96 kg K20/fed.) without Nitrobein. Results showed that Fuseau cuttvar was more infested by the four arthropods than Local cultivars. The least record of infestation was detected in treatment of Nitrobein + 75 % (RNPK) for both cultivars and both seasons, followed by Nitrobein + 50 % (RNPK). The highest infestation was recorded in the check treatment. The population of urticae and B. tabad were highly recorded in June, while May was the month of high population of A. gossypil and T tabad The begin of the season was characterized by the high population of the arthropods and declined steadily towards the end of the season.