A TFT-LCD array substrate and a manufacturing method thereof. The array substrate comprises a gate line, a data line, and a pixel electrode, and the pixel electrode is disposed in a pixel region defined by the intersection between the gate line and the data line. In the pixel region, a partition groove for forming a pixel electrode pattern is provided at the periphery of the pixel electrode. This structure is helpful to form a pixel electrode pattern by a lift-off process, which significantly reduces the production cost and improves the production yield.