For the single-molecule level quantitative measurement of target mRNAs attached on the DNA chip, one of the most important things is how to maintain the homogeneous, desirable-spaced arrangement of DNA-probes on the surface of the chip. Thus we have developed the novel method for decorating DNA-probes on the chip with desired intervals and homogeneous concentration applying the vapor deposition polymerization (VDP) technique, in which hexamethylene diisocyanate (HDI) and 3,5-diaminobenzonic acid (DBA) molecules were polymerized directly on the chip to form the polymer thin layer. The interval of the reactive carboxyl-group (-COOH) on the side-chains of DBA was controlled to become 2.0 nm by choosing another molecule having this length (HDI). After we made 10-nm-thick HDI-DBA polymer film on the chip, we attached amine-group of the thiol-, amine-decorated DNA-probe to the carboxyl-group of DBA. Then we checked the spatial arrangement and homogeneity of DNA-probes attached on the polymer film using 20-nm gold (Au) nano-particles. By the scanning electric microscopy observation, we first confirmed the spatial distribution of Au nano-particles on the chip was 254 particles/μ m2, whereas the less than 1 particles/μ m2 for the control sample, in which no DNA-probe was attached on the film. Moreover, the standard deviation of localization of particle distribution was less than 8 particles differences / 254 particles/μ m2, which is a magnitude better than the conventional silane-coupling method. The result indicates the potential of our method to form the homogeneous DNA-probe surface on the.