We investigated an oxygen-deficient TiO2(110) surface using noncontact atomic force microscopy, revealing the defect structures of topmost oxygen atoms. We successfully observed not only half-height steps along the [1 (1) over bar 2] direction caused by crystallographic shear planes belonging to the {132} family but also novel half-height steps along [001]. The ten-ace between the half-height steps along the [1 (1) over bar 2] direction was terminated with added Ti2O3 rows including some defect structures. We proposed that the half-height steps along the [001] direction were formed together with the half-height steps along the [1 (1) over bar 2] direction.