Objective To investigate the influencing factors involved in the establishment of a C57BL/6 J model of metastatic melanoma in the lung, including the way of tumor inoculation, the number of inoculated cells and the time of tumor formation. Methods Mouse melanoma B16F10 cells were cultured in vitro. 1) Eighteen healthy male C57BL/6 J mice were randomly divided into three groups. Mice in each group received 100 μL cell suspension (including 3 × 10⁶ melanoma cells) via intravenous, intraperitoneal and subcutaneous injection, respectively. After two weeks, the mice were killed and dissected, and the tumor growth and metastasis were observed. 2) Eighteen male mice were randomly divided into three groups. Mice in each group were injected with 3 × 10⁶ cells, 1 × 10⁶ cells, and 3 × 10⁵ cells through the tail vein, respectively. After two weeks, mice were killed and dissected, and the tumor growth and metastasis were observed. 3) Eighteen male mice were randomly divided into three groups. Mice in each group were injected with 1 ×10⁶ cells though the tail vein. Mice were killed and dissected after one week, two weeks and three weeks, respectively. The growth and metastasis of tumor were observed. Results 1) The success rate of lung metastasis was 100% in the mice with intravenous injection, but not in mice receiving intraperitoneal injection and subcutaneous injection. 2) The size of metastatic melanoma nodules were moderate in mice inoculated by 1 ×10⁶ cells. The number of melanoma metastatic foci was too high in the mice inoculated with 3 ×10⁶ cells, but too low in the mice inoculated with 3 ×10⁵ cells. 3) Significant metastatic melanoma foci were observed in the mice killed and dissected after two weeks with no death. The number of melanoma foci in the lung was too high in the mice killed after three weeks, while was too low in the mice killed at one week after tumor cell inoculation. Conclusions Intravenous injection of 1 ×10⁶ mouse melanoma cells into C57BL/6 J mice and killed after two weeks is an optimal method for establishment of a mouse model of metastatic melanoma in the lung, and is worth of recommendation.