Population density and bitting behaviour of insect vectors are several of the factors that influence the number of cases of malaria. This study aims to determine the relationship between population density and bitting behaviour Anopheles farauti which is a vector of malaria in coastal ecosystems (Biak Numfor Regency) and swamp ecosystems (Asmat Regency) with malaria cases. The method used is human landing collection conducted at 18:00 to 6:00 a.m. inside and outside the house. The results showed that the population density of An. farauti in coastal ecosystems is relatively lower than the swamp ecosystems. Man bitting rate in coastal ecosystems is 4 and 4.66, at 95.52 and 42.38 in swamp ecosystem. An. farauti on two ecosystems research are eksofilik. Population density and bitting behaviour An. farauti in coastal ecosystems and swamp ecosystems are not positively correlated with the number of malaria cases.