What I intend to show in this paper can be summe\arized as follows: first, I investigated as literally as possible Cajetan's doctrine of analogia attributionis that can evidently be regarded as a type of interpretation on St. Thomas' doctrine of analogia secundum intentionem tantum. Secondly, being led by both, some preliminary works of Penido and Gilson, and the full-scaled studies of Thomistic analogy by Lyttkens and Klbertanz, I observed what St. Thomas meant by the expression of analogia secundum intentionem tantum. Finally considering the Platonic character in St. Thomas' doctrine of analogia secundum intentionem tantum, I examined if this type of analogy can be truely metaphysical analogy in Thomistic philosophy.