Objective:To determine fauna and some ecological aspects of Anopheles mosquitoes in northeast of Iran.Methods:In this descriptive study,3 villages in Kalaleh County were selected in different geographical zones.Anopheles mosquitoes were collected biweekly from May to October using standard dipping method for larvae,and hand catch,total catch,artificial pit shelter as well as night-biting collections on human and animal baits for adults.Results:Totally 399 larvae and 2 602 adults of Anopheles mosquitoes were collected and identified as 2 species:Anopheles superpictus s.l.(An.superpictus s.l.) and Anopheles maculipennis s.l.The dominant species was An.superpictus s.l.(92.1%).Activity of these mosquitoes found to be started from middle of May and extended till September with two peaks of activity in July and August.Conclusions:An.superpictus s.l.as one of the main malaria vectors in Iran as well as some other parts of the world is the dominant species in the study area.This species has high potential for transmission and possibility of establishing a transmission cycle with low abundance.Other species,Anopheles maculipennis s.l.also has introduced as a malaria vector in northern parts of Iran.As this Anopheles is a complex species,genetic studies are recommended to determine the members of this complex in the study area. Objective: To determine fauna and some ecological aspects of Anopheles mosquitoes in northeast of Iran. Methods: In this descriptive study, 3 villages in Kalaleh County were selected in different geographical zones. Anopheles mosquitoes were collected biweekly from May to October using standard dipping method for larvae, and hand catch, total catch, artificial pit shelter as well as night-biting collections on human and animal baits for adults. Results: Totally 399 larvae and 2 602 adults of Anopheles mosquitoes were collected and identified as 2 species: Anopheles superpictus sl (An.superpictus sl) and Anopheles maculipennis slThe dominant species was An.superpictus sl (92.1%). Activity of these mosquitoes found to be started from middle of May and extended till September with two peaks of activity in July and August .Conclusions : An.superpictus slas one of the main malaria vectors in Iran as well as some other parts of the world is the dominant species in the study area.This species has hi gh potential for transmission and possibility of establishing a transmission cycle with low abundance. Other species, Anopheles maculipennis slalso has introduced as a malaria vector in northern parts of Iran. As this Anopheles is a complex species, genetic studies are recommended to determine the members of this complex in the study area.