A molding method for a BGA semiconductor chip package comprising a substrate supporting an array of chips having two lines of bonding pads formed at two respective side thereof. The molding method comprises the steps of: (A) providing a molding apparatus comprising a molding die having a molding cavity and at least two runners connected to the molding cavity; (B) closing and clamping the molding die in a manner that the chips are located in the molding cavity thereof; (C) transferring a molding compound into the molding cavity wherein each chip is arranged in a manner that the two lines of bonding pads thereof are substantially perpendicular to the flowing direction of the molding compound; (D) curing the molding compound; and (E) unclamping and opening the molding die to take out the molded product.