Abstract: Objective : To establish a human ovarian sarcomatoid carcinoma cell line, and study its biological characteristics. Methods : A specimen derived from metastatic tumor of a hu-man ovarian sarcomatoid carcinoma was obtained and cultured in vitro. The morphology of the cells was observed by microscope and electromicroscope. Growth curve, karyotype analysis, cultur-ing in soft agar, nude mice transplantation, immunohistochemistry etc., were used to investigate its biologic characteristics. Results : After primary culture, a new ovarian carcinoma cell line BUPH: O+SC-1 was established from human ovarian sarcomatoid carcinoma for the first time. The cell line has been maintained for over 100 passages during 13 months. The HE stain finding of trans-planted tumor showed that the cells were morphologically sarcomatoid. However, the transmission electron microscopic observation exposed that the cells were epithelial origin. The cells grew exu-berantly. The karyotype was pseudodiploid, with three chromosome markers. The cells could form clony in soft agar. The transplanted tumor has been growing rapidly and was similar to the origi-nal human tumor by histologic observation. The histochemical staining of AB-PAS, immunocytochemical stainings of CK7 and Yimentin were all positive. Those exposed its high malignant characteristics. Conclusions : BUPH: O+SC-1 was demonstrated as a high malignant human ovari-an sarcomatoid carcinoma cell line, which could be a useful model for the study in human ovari-an sarcomatoid carcinoma.