This study evaluated the effectiveness of ore particle size on column bioleaching from low-grade uranium ore using an indigenous Acidithiobacillus ferrooxidans, isolated from local uranium ore. The uranium content was 0.033% by weight and ore particle size was crushed to < 50 mm, < 30 mm, and < 15 mm. The additive content of sulfuric acid 5 g/L, Fe3+ dosage of 5.0 g/L, spray strength of 2.57 L/(h.m(2)) and temperature of 25 degrees C were controlled. After 150 days of leaching, acid consumption amounted to 2.73 g H2SO4 per kg ore, the obtained maximum uranium extraction was 64.85% with the ore particle size of < 15 mm. The results showed that a smaller particle size ore had a higher uranium extraction and that an economic uranium extraction can be obtained by correctly controlling the ore granularity.