By using ab-initio methods to investigate blue-shifting hydrogen bond from the interaction of HCOOH with XCHO (X=H, F, Cl, Br), twenty-eight stable complexes with eight different structures were observed on potential energy surface. Based on interaction energy corrected by ZPE and BSSE contributions at the CCSD(T)/aug-ccpVDZ//MP2/aug-cc-pVDZ level, the stability of complexes with the same X components decreases as follows: G7 G8 G1 G2 G5 G3 G6 G4. The obtained results indicate that there are existences of the blue shifting hydrogen bonds of C-H...O and C-H...X (X = F, Cl, Br) in the twenty-four complexes of interaction between HCOOH and XCHO. Furthermore, the present study shows that, as a result of complexation, the magnitude of blue shi ft of C-H stretching frequency, as compared to that in the respective monomer, decreases when one H in HCHO is substituted by one X, with X = F, Cl, Br. It is also remarkable that a contraction of C-H bond length and a blue shift of its stretching frequency in comparison with relevant monomer are contributed by both an increase in s-character percentage of Chybrided orbital and a decrease in population of (C-H) electron density. However, the first factor plays a significant role in determining the blue shift of C-H bond upon complexation.