Abstract: The karyotype of Paragonimus westermani from Lanting Commune, Shaoxing County, Zhejiang Province, was investigated by the cell cultivation method of Tera-saki with slight modification; The chromosome number is 2n = 22, and the karyotype consists of one pair of large-sized metacentric, four pairs of medium-sized subtelocen trics, four pairs of small-sized submetacentrics and two pairs of small-sized metacen tries. These results are basically coincident with the diploid type of P. westermani presented by He Lianyin et al in 1982. In addition, spermatozoa were found in 98.0% of seminal receptacles of the adult worms, suggesting that this worm belongs to the bisexual type of P. westermani described by Terasaki. Since the worms under our observation were collected from the endemic area of paragonimiasis, it was suggested that P. westermani with diploid pattern (or bisexual type) might cause typical pulmonary manifestations.