Abstract: The human abdominal malignant mesothelioma cell line (AMS-82) was established. Since March 1987, it had been transf eyed for 150 generations. This cell showed the following characters: 1. The. pathological features of the transplating tumor in BALB/C(nu/nu)mice was similar to that of the original inoculated lesion. 2. Microscopically,the majority cells of the cell line were shuttle-like with abnormal mitotic figures and 2-4 nucleli. 3. ELetron microscopically, there were rich microvilli on the surface of the cell. Abundant ribosomes were also observed but no desmosomes. 4. The growth curves of 94th passages were determined. The doubling time was 43 hours. The mitotic indez attained peak on 7th day(82%). 5. The numbers of the chromosomes ranged from 47 to 145. The majority cells of the cell line may be considered as the tetraploid.