Abstarct: Dendrimers as nano drug delivery systems have become a promising approach to conjugate with a variety of interesting targeting molecules (drugs) with desired water solubility and biocompatibility. The relatively hydrophobic interior of the dendrimers allows for physical encapsulation of hydrophobic cancer drugs such as curcuminoid to improve the water solubility and bioavailability of these drugs. In this research, the interaction of two dendrimers of different compositions poly (amidoamine) (PAMAM) and the poly(phenylenevinylene)-polyamidoamine (PPV-PAMAM) with hydrophobic drugs curcumine (CUR) and bisdemethoxy-curcumin (bDMC) were studied using the theoretical calculations. PPV-PAMAM or Transgeden dendrimer is a novel hybrid dendrimer that combines a conjugated rigid PPV with flexible PAMAM .Calculations at the B3LYP level of theory with 6-31G** basis set were performed to analyse the molecular structure, electronic properties and binding energy of two complexes of PAMAM and TGD with CUR and bDMC. Because of calculations of some properties such as thermodynamics functions require costly and time consuming computations as the size of the dendrimers increase, the low generations (G1 and G2, i.e PAMAM/G2 and TGD/G1) were used for this investigation. After optimizations of these two complexes, the structure parameters, binding energies, dipole moments, the chemical reactivity indices, thermodynamics functions and HOMO-LUMO energies (HLG) were calculated at the B3LYP/6-31G (d,p) level of theory. The results of calculations showed that CUR, and bDMC located mainly in the binding cavities of dendrimers through hydrophilic contacts i.e. through of two intermolecular H-bond (O-H···O=C-den, and O-H···N-H-den). The values of the binding energy, thermodynamics functions, and the gap energies of HLG for the capsulation of bDMC and CUR in the above mentioned dendrimers indicated that CUR has a stronger interaction with PAMAM compared to TGD, and bDMC is more stable in the complexation of TGD than PAMAM. The results of dipole moments, partial charges and HOMO-LUMO structures of these complexes provided the charge transfers from bDMC to dendrimers.