Narrow-bore　open　capillaries　without　stationary-phase　coatings　were　used　for　DNA　chromatographic　separation　in　free　solution.　The　retention　behaviors　of　various　sizes　of　DNA　fragments　were　investigated　using　1　x　TE　buffer　as　the　eluent　at　various　temperatures.　It　was　shown　that　the　temperature　was　an　important　parameter　affecting　the　speed　of　DNA　separation,　with　little　loss　of　resolution　in　narrow-bore　open-capillary　chromatography.