Wireless Sensor Network (WSN) consists of a large number of sensor nodes. Determining the actual position of each sensor node is thus difficult. Finding the exact position of each sensor forms the basis of localization. Localization in wireless sensor network refers to finding position of unknown nodes based on position of known nodes known as anchors or reference nodes. This paper proposes centroid localization method using edge weights of adjacent nodes based on fuzzy modeling for 3D environment. In proposed method neighboring adjacent anchor nodes that are near to unknown sensor node are detected first and then fuzzy membership functions for edge weights based on received signal strength is developed.