Titanium oxide nanotubes with Ca ions on their surfaces were prepared as 2 mm cylindrical inserts and placed into surgically created bone defects in the femurs of Wistar rats. On day 3, fibroblast-like cells were present on the surface of the nanotube inserts and fibers were observed by scanning electron microscopy (SEM). On day 7, cells with alkaline phosphatase activity were present and identified as osteoblasts by SEM and transmission electron microscopy. New bone matrices were observed in and around the porous nanotube inserts by light microscopy. Compared with clinically used hydroxyapatite and tricalcium phosphate, beta-titanium oxide nanotubes promote faster acquisition and development of osteoblasts and bone tissues and have better bone regenerating ability after one week.