A steering assist apparatus comprises a steering assist control means for performing a lane tracing assist control (LTA) and a lane changing assist control (LCA) and a non-holding determination means for determining whether or not a first non-holding condition that a non-holding duration time is more than or equal to a first time is satisfied and whether or not a second non-holding condition that the non-holding duration time is more than or equal to a second time shorter than the first time is satisfied. The steering assist control means raises a warning when the second non-holding condition becomes satisfied and stops the LTA when the first non-holding condition becomes satisfied while performing the LTA, and raises a waring when the second non-holding condition becomes satisfied whereas continues the LCA until a completion condition of the LCA becomes satisfied regardless of the non-holding while performing the LCA.