Dengue is a viral fever. Its virus is carried by Ades. Ades is a large mosquito. It is of two types. One is Aegyptic and the other is Alecopiptus. It lays eggs on stagnant water of pots and containers. This mosquito spreads dengue fever. This fever is of two kinds, One is classical and the other is hemorrhagic. The dengue affected person shows some symptoms. He/she feels severe pain in muscle and bone. His/her bodily temperature goes up from 104° to 105°F. He/she feels like vomiting. Rash is seen on the body after three or four days of the attack of fever. By throwing away the standing and transparent water of pots, vases and containers we can prevent this mosquito. Besides, by keeping environment neat and clean, we can prevent this mosquito.