A package structure, and a RDL structure are provided. The package structure incudes a die and a RDL structure electrically connected to the die. The RDL structure includes a first redistribution layer, a second redistribution layer and a third redistribution layer. The first redistribution layer includes a first ground plate. The second redistribution layer includes a second ground plate and a signal trace. The signal trace is laterally spaced from the second ground plate. The third redistribution layer includes a third ground plate. The third redistribution layer and the first redistribution layer are disposed on opposite sides of the second redistribution layer. The signal trace is staggered with at least one of the first ground plate and the third ground plate in a direction perpendicular to a top surface of the signal trace.