The invention discloses curcumin derivatives as shown in formula (I), and preparation and application thereof. The invention provides new curcumin derivatives which have antineoplastic activity, and are applicable to preparation of antineoplastic medicaments. The curcumin derivatives have different degrees of proliferation inhibition effects on liver cancer cell SMMC-7721, human breast cancer cell MCF-7, and human prostate cancer cell PC-3. Some compounds have higher activity than curcumin, and have an inhibitory concentration 50% (IC50) of up to a level of about 10 [miu]M; the new curcumin derivatives also have very good antioxidant activity, and have different degrees of removing activity on free radical ABTS and DPPH; the curcumin derivatives of I-4, I-7 and I-3 have the activity of ABTS free radical removal 5.2 times, 3.4 times, and 3.3 times higher than that of curcumin, and these new derivatives are applicable to antioxidant additives of medicines and food.