A cowl structure of a vehicle includes: A-pillars vertically arranged at both sides of a vehicle body; an apron upper member arranged on a front of each of the A-pillars to be longitudinally elongated therefrom; a shock absorber housing formed under the apron upper members; a cowl transversely arranged between the apron upper members; and an engine compartment extension panel connected between the cowl and the apron upper member so as to form an extended plane on both sides of the cowl corresponding to the cowl. The apron upper member is integrally formed with the A-pillar in the longitudinal direction of the vehicle body, and both sides of the cowl are cut along the shape of the engine compartment extension panel so as to correspond to the engine compartment extension panel.