Objectives To explore the effects of curcumin and cisplatin on A549 lung cancer cell invasion and metastasis, and explore the influence of the two drugs on matrix metalloproteinase 9 (MMP-9) and E-cadherin protein. Methods MTT assay was performed to detect the effects of curcumin, cisplatin alone and the combination on A549 lung cancer cell proliferation. Transwell assay was performed to detect the effects of curcumin, cisplatin alone and the combination on the invasion and metastasis of lung cancer cells. Western blot was used to detect the protein expression of MMP-9 and E-cadherin. Results The proliferation inhibition of A549 lung cancer cell rate in 5, 10, 20, 40 μmol/L of curcumin was 6.50%±1.06%, 11.70%±0.88%, 22.97%±0.82%, 27.93%±0.94%, respectively. Compared with control group, the proliferation inhibition rates in four different curcumin groups were significantly increased (all P<0.01). The differences in the proliferation inhibition rates among four different curcumin groups were statistically significant (allP<0.05). The proliferation inhibition rates of A549 lung cancer cell in 1, 2, 4 mg/L of cisplatin were 7.12%±0.86%, 20.07%±1.14%, 26.88%±0.51%, respectively. Compared with control group, the proliferation inhibition rates in three different cisplatin groups were significantly increased (allP<0.01). The differences in the proliferation inhibition rates among three different cisplatin groups were statistically significant (allP<0.01). The proliferation inhibition rates of A549 lung cancer cell in curcumin (20 μmol/L) combined with cisplatin (1, 2, 4 mg/L respectively) were 28.37%±0.57%, 39.72%±0.64%, 46.27%±0.86%, respectively. Compared with control group and curcumin or cisplatin used alone, the proliferation inhibition rates of three combined groups were significantly increased (allP<0.01). The invasion inhibition rates of A549 lung cancer cell in curcumin group (20 μmol/L), cisplatin group (2 mg/L) and combined group (curcumin 20 μmol/L plus cisplatin 2 mg/L) were 38.62%±0.23%, 36.52%±0.33%, 63.78%±0.59%, respectively. Compared with control group and curcumin or cisplatin used alone, the invasion inhibition rates of combined group were significantly increased (allP<0.01). The protein grey values for curcumin group (20 μmol/L), cisplatin group (2 mg/L) and combined group (curcumin 20 μmol/L plus cisplatin 2 mg/L) were 0.768±0.047, 0.654±0.104, 0.684±0.008, 0.444±0.104 (MMP-9) and 0.603±0.170, 0.792±0.050, 0.784±0.045, 0.879±0.110 (E-cadherin), respectively. Compared with control group and curcumin or cisplatin used alone, the protein grey values of combined group were significantly different (allP<0.01 orP<0.05). Conclusions Curcumin and cisplatin combination can inhibit the invasion and metastasis of lung cancer A549 cells. Its mechanism may be related to downregulating MMP-9 and upregulating E-cadherin.