The growth, migration and spread of malignant tumors requires a large number of new blood vessels to supply nutrients. In our previous study, it was found that the hyaluronic acid (HA) modified novel antiangiogenic peptide ES2-AF has better solubility, longer half-life, stronger targeting than non-modified ES2-AF, and it significantly inhibited the formation of new blood vessels. In the current work, we studied the stability of ES2-AF after HA modification, including heat stability, longterm stability, and pH stability. After treatment with HA-ES2-AF, cell apoptosis and the cell cycle were analyzed using flow cytometry. The inhibitory effect of HA-ES2-AF on tumors was investigated in vivo in HepG2 tumor-bearing nude mice. All the above results showed that HA-ES2-AF significantly improved stability, effectively induced apoptosis of endothelial cells, caused G1 phase arrest of endothelial cells, and decreased the percentage of cells in G2 and S phases. In vivo, HA-ES2-AF exhibited an inhibitory effect on tumors growth. In addition, the results provide a reliable basis for studying the inhibition of neovascularization and anti-tumor drugs in the future.