A communication device, comprising: a multi-band antenna package structure (1, 2, 3), comprising: a first redistribution layer, comprising a first dielectric material layer and first metal patterns formed in openings of the first dielectric material layer; an integrated circuit layer, formed on the first redistribution layer, comprising at least one metal via, at least one metal pillar, an integrated circuit chip (100, 100', 100"), and a molding layer, wherein the molding layer is used to fill openings formed by the metal via, the metal pillar and the integrated circuit chip (100, 100', 100") which are disposed on the first redistribution layer, the metal via is electrically connected to one of the first metal patterns, and the metal pillar is electrically connected to the integrated circuit chip (100, 100', 100") and one of the first metal patterns; a second redistribution layer, formed on the integrated circuit layer, comprising a second dielectric material layer and second metal patterns formed in openings of the second dielectric material layer, wherein the metal via is electrically connected to one of the second metal patterns; and a first antenna unit layer, comprising a first dielectric layer and third metal patterns formed in openings of the first dielectric layer, wherein at least one of the third metal patterns is electrically connected to one of the second metal patterns, and the third metal patterns form a first antenna unit; wherein the multi-band antenna package structure (1, 2, 3) comprises a first shielding layer, formed between the first antenna unit layer and the second redistribution layer, comprising a second dielectric layer and fourth metal patterns formed in openings of the second dielectric layer, wherein the fourth metal patterns are electrically connected to the third metal patterns and portions of the second metal patterns. a multi-band antenna package structure (1, 2, 3), comprising: a first redistribution layer, comprising a first dielectric material layer and first metal patterns formed in openings of the first dielectric material layer; an integrated circuit layer, formed on the first redistribution layer, comprising at least one metal via, at least one metal pillar, an integrated circuit chip (100, 100', 100"), and a molding layer, wherein the molding layer is used to fill openings formed by the metal via, the metal pillar and the integrated circuit chip (100, 100', 100") which are disposed on the first redistribution layer, the metal via is electrically connected to one of the first metal patterns, and the metal pillar is electrically connected to the integrated circuit chip (100, 100', 100") and one of the first metal patterns; a second redistribution layer, formed on the integrated circuit layer, comprising a second dielectric material layer and second metal patterns formed in openings of the second dielectric material layer, wherein the metal via is electrically connected to one of the second metal patterns; and a first antenna unit layer, comprising a first dielectric layer and third metal patterns formed in openings of the first dielectric layer, wherein at least one of the third metal patterns is electrically connected to one of the second metal patterns, and the third metal patterns form a first antenna unit; a first redistribution layer, comprising a first dielectric material layer and first metal patterns formed in openings of the first dielectric material layer; an integrated circuit layer, formed on the first redistribution layer, comprising at least one metal via, at least one metal pillar, an integrated circuit chip (100, 100', 100"), and a molding layer, wherein the molding layer is used to fill openings formed by the metal via, the metal pillar and the integrated circuit chip (100, 100', 100") which are disposed on the first redistribution layer, the metal via is electrically connected to one of the first metal patterns, and the metal pillar is electrically connected to the integrated circuit chip (100, 100', 100") and one of the first metal patterns; a second redistribution layer, formed on the integrated circuit layer, comprising a second dielectric material layer and second metal patterns formed in openings of the second dielectric material layer, wherein the metal via is electrically connected to one of the second metal patterns; and a first antenna unit layer, comprising a first dielectric layer and third metal patterns formed in openings of the first dielectric layer, wherein at least one of the third metal patterns is electrically connected to one of the second metal patterns, and the third metal patterns form a first antenna unit; wherein the multi-band antenna package structure (1, 2, 3) comprises a first shielding layer, formed between the first antenna unit layer and the second redistribution layer, comprising a second dielectric layer and fourth metal patterns formed in openings of the second dielectric layer, wherein the fourth metal patterns are electrically connected to the third metal patterns and portions of the second metal patterns.