Single cell clones were isolated from metastatic human lung giant cell carcinoma (PG) using limited dilution method. After preliminary screening by in vitro invasion assay, tumorigenicity and spontaneous metastasis assay in nude mice, three cloned PG cell sublines (PGBE1, PGCL3 and PGLH7) were selected for further observation on morphology, chromosome number, in vitro growth and invasion assays, tumorigenicity and spontaneous metastasis to lung and lymph nodes in nude mice. We found that there was some difference on spontaneous metastasis to lung and lymph nodes in nude mice and in vitro invasive abilities between PGBE1 and PGLH7. But there were no obvious differences in other biological features among the three sublines. The results show that the PG cell line consists of different subpopulations of cells with different metastatic properties. These sublines may be valuable for further study on the molecular mechanisms of cancer metastasis.