Methanol extracts of the aerial parts from 31 Euro-Asiatic plant fourth instar larvae species were tested for larvicidal activity against the mosquito, Culex quinquefasciatus Say (Diptera: Culicidae) fourth instar larvae. under laboratory conditions. The mortality from six concentrations (5, 10, 25, 50, 100 and 200 ppm) was determined and LD50 was calculated. All plant extracts showed larvicidal activity in 24 h exposure tests. The methanolic extracts of plants Otanthus maritimus displayad the highest larvicidal activities with LD50 7 ppm, followed by Ammi visnaga , Acer pseudoplatanus, Acer platanoides and Satureja hortensis with LO50 9, 23, 28 and 28 ppm, respectively.