The purpose of this study was to develop a lipid emulsion of tanshinone IIA (Tan IIA-LE) for intravenous administration and to investigate its feasibility for future clinical practice. The formulation was optimized using central composite design-response surface methodology (CCD-RSM), and the homogenization process was investigated systematically. The Tan IIA-LE was evaluated in terms of stability, safety and in vitro anti-hepatoma activity. The formulation of Tan IIA-LE is composed of 0.05% (w/v) Tan IIA, 20% (w/v) soybean oil–MCT mixture (1:1, w/w), 1.2% (w/v) soybean lecithin, 0.3% (w/v) F68 and 2.2% (w/v) glycerol, a high pressure homogenization at 100 MPa for 3 cycles was selected as the optimal homogenization process. The Tan IIA-LE was light-sensitive but stable for at least 12 months at room temperature in dark. The safety study demonstrated that the Tan IIA-LE did not cause venous irritation or obvious acute toxicity. Furthermore, the Tan IIA-LE displayed significant anti-tumor activity against human hepatoma cell lines in vitro. Overall, the Tan IIA-LE developed in this study was suggested to be a suitable and safe dosage form of Tan IIA for intravenous administration and has potential in liver cancer therapy in future.