Despite the importance of in vitro study of gastric cancer, the established cell lines derived from human gastric carcinoma are very few. We have recently established a new cell line derived from human gastric cancer which has the ability to produce several tumor markers. This cell line has been designated JR-1. The cancer cells were obtained from the cerebrospinal fluid of a 37 year-old female patient who had metastatic brain tumor of the poorly differentiated gastric adenocarcinoma. The cells were inoculated into the tissue culture flask containing Ham's F-12 medium supplemented with 10% fetal bovine serum, antibiotics. Within 24 hours, the cells attached to the surface of the flask and started to grow. The first subcultures were performed at 1 week, and subsequent subcultures have been done once a week. This cell line has been maintained for more than 15 months through 60 passages with a stable growth. Chromosome analysis of the cells was performed. The doubling time of the 20th passage was 72 hours. Under phase contrast microscopy, monolayered pavement-like cell arrangement was observed. PAS staining showed intracellular mucin granules. Transmission and scanning electron microscopy revealed spindle-shaped cells with numerous microvilli and fine projections as well as intracellular granules, indicating mucin. Tumor markers produced by this cell line were CEA, CA19-9, TPA and Procollagen III.