Peptides have been intensively studied in pharmaceutical industries because of their versatile structures and activities. Peptide conjugation to bioactive molecules is a simple and very efficient approach to modulate the inherent biological activities of those molecules by altering their chemical and physical properties without safety concerns.1 Previously, we have reported that caffeic acid-peptide conjugates, esp., caffeoyl-prolyl-histidine amide (CA-PH) showed a strong antioxidant activity compared to caffeic acid alone,2 and the structural effect was investigated in molecular level for the enhanced antioxidant activity. To understand the effect of antioxidant activity in cell systems more clearly, we examined its antioxidative protection of vascular smooth muscle cells (VSMCs), and found that CA-PH significantly reduced hydrogen peroxide-induced reactive oxygen species (ROS) generation and increased the expression of heme oxygenase-1, which led to inhibition of abnormal proliferation of VSMCs.3 We further applied peptide conjugate concept to α-Resorcylic acid (RA) to improve its biological activities. RA-phenylalanine amide (RA-F) boosted collagen synthesis and reduced the expression level of matrix metalloproteinases in human fibroblasts, which can result in prevention of photo-aging and related diseases.4 More examples of peptide bioactive compound conjugates will be presented These studies have provided a new avenue in developing potent cosmeceutical and pharmaceutical agents.