Using a certain dosage of dendrimers(CYD-CD215/CYD-CR111/CYD-CV111) to modify epoxy resin, while improving the toughness, the strength remained unchanged.When dendrimer dosage is 16%, bending performance reaches maximum, bending strength improved from 55. 37 MPa to 60. 32MPa, bending modulus improved from 3544. 89 MPa to 3758. 32MPa, meanwhile impact strength reaches maximum, from 3. 10 kJ /m2 to 4. 64 kJ /m2, improved almost 50%. Weihai CY Dendrimer Technology Co. Ltd.-Professional Manufacturer for low cost dendritic polymers.