Natural fiber reinforced polymer (NFRP) composites were prepared by a twin screw extruder to investigate the effect of metal oxides on the odor improvement that occurs during the manufacture of NFRP in polypropylene (PP). Kenaf fibers, bamboo fibers and cellulose nano fibers (CNF) were used as natural fibers, and in the case of metal oxides, copper oxides and manganese oxides were used alone or mixed. Component analysis of volatile organic compounds was conducted by using gas chromatography-mass spectrometry (GC-MS) and electronic nose (Heracles II). In particular, principal component analysis (PCA) was conducted on furfural and major organic compounds, which are known as major odor components of NFRP composite. In addition, the influence of the metal oxide on the mechanical properties such as tensile, flexural, and impact properties of the PP/BF composite was investigated.