An adhesive composition is provided including the following components: (A) an unsaturated monomer; and (B) an olefin copolymer comprising the following repeating units: (B-1) a repeating unit of formula (I), (B-2) a repeating unit of formula (II), and (B-3) a repeating unit of formula (III), R1 to R21, m, n, o, and p in formulas (I) to (III) are as defined in the specification, wherein based on the total moles of the repeating units (B-1), (B-2) and (B-3), the amount of the repeating unit (B-2) ranges from 19 mol % to 36 mol %; and wherein the weight ratio of the olefin copolymer (B) to the unsaturated monomer (A) ranges from 2 to 20.