Laboratory tests for measuring absorption, porosity, P-wave velocity and uniaxial compressive strength (UCS) were performed to examine weathering characteristics of ilmenite by microorganism. Physical property changes were quantitatively estimated with comparing culture period on the condition of abiotic oxidation without microorganism and biooxidation with microorganism. As a result, the measured pH during 45 days was distributed in the range from 3.82 to 4.26, on the other hand, biooxidation showed the range from 2.20 to 2.57. The measured absorption according to microorganism and culture period represented 0.052% at final stage in the case of abiotic oxidation and 0.073% in the case of biooxidation. Porosity showed 0.206% at final stage in the case of abiotic oxidation and 0.281% in the case of biooxidation. In general, the values by biooxidation showed higher than that by abiotic oxidation. Change range of P-wave velocity with culture period showed that the measured value as 1410 m/s at final stage in the case of biooxidation was lower than 1886 m/s of that in the case of abiotic oxidation. The UCS was decreased with increasing culture period in all specimens and represented 241.1 MPa at final stage in the case of abiotic oxidation and 140.0 MPa in the case of bioxidation. In conclusion, it implies that influence of physical property on ilmenite by biooxidation related with microorganism was larger than that by abiotic oxidation.