Using loess as the base material，the ecological interior wall latex paint was prepared by modification，emulsification and dispersion processes. Taking the main performance of theinteriorlatex paint as an indicator，the single factor controlled variable approach was used to optimize the loess modification process（dosage，calcination temperature and time）and the formulation of latex paint. The results showed that the latex paint prepared by incorporation of calcinated loess at 15% on total formulaion，which was calcinated at 450 ℃ for 90 minutes at constant temperature，provided the best properties. The product was fully in line with and superior to the requirements instandard of“synthetic resin interior wall latex coatings（GB / T9756—2009）” . It was characterized by its low cost，simple technology，environmental friendly，and good practical application prospects.