Introduction: In the recent years, the over use of pesticides is not only following by the health hazardous and environmental problems, but also leading to the resistance of the pests to pesticides. Therefore, it is necessary to find a proper, safe, durable and economic method in order to get rid of them thoroughly. Hence, the use of pest repellents which have been prepared from Juglans regia L is an Idean method in the prevention of several diseases. In the traditional medicine, different parts of the Juglans regia L have been used for the various purposes. It has been reported that the leaf extract of this plant is anti-inflammatory analgesic, antioxidant and with other biological properties. The present study aims to identify and use the domestic plants which are pest repellent and safe for man.

Methods: In this experimental laboratory Research, the Juglans regia L leaves were collected from the natural growing regions of Sari Township (central, Asfyord district, the Galeh Kola Sofla, Kordkhayl Village). After drying, the leaf extraction was performed. The concentration of 50,100and250mg/kg were prepared and spread on the skin of Albino Gunipig. After 30 minutes, the number of the Culex pipiens bites on the skin area was recorded and statistical analysis was performed.

Result: The mean repelling effect comparison of the leaf extract on the Culex pipiens showed at high concentrations of leaf extracts of Juglans regia L, blood feeding of insects was less observed and in these various concentrations, significant difference was reported (P=0.001) the highest repelling property was correlated with the concentration of 250mg/kg of Juglans regia L extract and the repelling effect was73.36%.

Conclusion: The metanolic Juglans regia L leaf extract effect on the c.pipiens, showed that the repelling effect of the extract goes up with the increase of the extract concentration. The efficacy percentage for the average concentration was49.78% in animal experiments. Therefore, it is recommended to use  Juglans regia L leaf extract in the preparation of this product in order to prevent the culex pipiens bite.