Newcastle disease virus (NDV), avian paramyxovirus type 1 is the causative agent of Newcastle disease which is a highly contagious disease of poultry worldwide. NDV exists in two distinct classes, class I(genotypes 1-9) and class II(genotype I-XI), within a single serotype. Class I viruses are found in waterfowl, live bird markets and domestic poultry.  KR/duck/01/06(DK1) was isolated from domestic ducks during 2006/2007 winter season in Korea. DK1 was classified as Class I genotype 2 based on partial F gene and characterized as lentogenic NDV through pathogenicity test. The complete genome of DK1 contained 15,198 nucleotides, which conformed to the "rule of six", and consists of six genes in the following order: 3'-NP-P-M-F-HN-L-5'. The leader and trailer sequences were 55 and 17 nt in length. The cleavage site for the F protein in DK1 was 112ERQERL117. The HN protein in DK1 consisted of 585 amino acids, which is similar to DE-R49/99. The linear epitope of DK1 HN protein is 345PDDQWYQV353, which is conserved among class I strains.  This is the first report of complete genome sequences of Class I NDV strain isolated in Korea.