Human lung cancer cell line, named KUM.LK-2 was established from xenograft implanted in nude mice and maintained for 43 months. And serially transplanted in nude mice. This line has the following biological characters. 1) Spontaneous lung metastases are made in nude mice inoculated subcutaneously. 2) This line can produce some kinds of proteases, like as tissue type plasminogen activator, urokinase type plasminogen activator and collagenase. 3) KUM.LK-2 has the ability of platelet aggregation.