The Melt spinning technique of Nano-titanium dioxide particles/PP/PLA composites filaments fabricated by plasma treated Nano-titanium dioxide particles studied in the present investigation. The experimental results showed that the physical and mechanical properties of Nano-titanium dioxide particles /PP/PLA composites filaments depended on the following factors of the percentage of Nano-titanium dioxide particles, the percentage of maleic anhydride (MAH), plasma treatment parameters: flow rate of helium gas, output power, sample treatment or stationary time and flow rate of oxygen gas. Among it the flow rate of oxygen gas had the significant influence on the filament properties of tensile modulus, the yield strength and the melting temperature. Stepwise multiple regressions orthogonal design method of system optimization used to determine the percent of contribution of each factor. It found that the three indicators were different by these analyses. The experimental results indicated that the optimized conditions by stepwise multiple regressions were better than that by traditional analysis.