Depressive rumination, which is defined as “repetitively focusing on the fact that one is depressed; on one’s symptoms of depression; and on the causes, meanings, and consequences of depressive symptoms” (Nolen-Hoeksema, 1991) had been reported as a risk factor for various mental illnesses. The purpose of this study was to investigate the factors that influence the persistence of ruminative thought during a Sustained Attention to Response Task (SART). Participants (25 women and 20 men) were randomly assigned to either a low cognitive group or a high cognitive group. Ruminative thoughts were induced in participants, who completed thought sampling during the SART. The analysis revealed that the reaction time of SART and the positive belief of depressive rumination influence on the persistence of ruminative thought.