Provided are a thin film transistor display panel, a liquid crystal display, and a manufacturing method therefor, that can prevent errors or omissions in rubbing due to a step between a pixel electrode and a data line, and the resulting light leakage, as well as increase the effective area ratio of a spacer and prevent shorts from occurring during at least some repair processes. The thin film transistor array panel includes: a first substrate; a gate line and a data line formed on the first substrate; a step preventing member formed on the data line to at least partially fill a volume positioned between the data line and a pixel electrode; and a spacer formed on the first substrate, wherein the spacer and the step preventing member comprise the same material.