Disclosed is an eco-friendly water-based paint composition for interior finishing materials of buildings. The eco-friendly water-based paint composition includes: 3 to 6 wt.% of diatomite for adsorbing harmful materials； 7 to 12 wt.% of titanium dioxide for enhancing a deodorization effect； 0.4 to 1.5 wt.% of antimicrobial agent-containing microcapsules for killing harmful microorganisms derived from an indoor air； 0.1 to 0.5 wt% of preservative for suppressing and preventing propagation of fungi derived from indoor air； 30 to 40 wt.% of an inorganic binder for binding different ingredients of the water-based paint composition so as to form a smooth surface； 3 to 10 wt.% of water for blending different materials for the water-based paint and controlling workability； and residual silica for forming thickness during painting as a base material of the water-based paint.
