The present invention relates to a compound of Formula (I) and the manufacturing method(s) thereof and the use thereof: Formula (I) wherein: Ar is a nitrogen-containing heteroaromatic ring group; X and Z are each a carbon atom, and so on; Y is CO, and so on; R1 is a hydrogen atom, and so on; R2 and R3 are each a hydrogen atom, and so on; R4 and R5 are each a hydrogen atom, and so on; and the formula is a single bond or a double bond. According to the present invention, the compound of the present invention can provide Cdk4 and/or Cdk6 inhibitors for treating malignant tumors, because the compounds of the present invention exhibit a prominent growth inhibitory activity against tumor cells.