LetG be a group of finite order andD ₀ = {e},D ₁,...,D _d be a partition ofG. Suppose{d ^–1|d [`(D)]<sub>i</sub> ,[`(D)]_j = å_{k = 0}^d p_ij^k [`(D)]<sub>k</sub>\bar D_i ,\bar D_j = \sum\limits_{k = 0}^d {p_{ij}^k } \bar D_k for alli, j where [`(D)]_m , = å_{g Î Dm} g Î \mathbbC[G]\bar D_m , = \sum\limits_{g \in D_m } g \in \mathbb{C}[G] . Then the subalgebra spanned by [`(D)]<sub>0</sub> ,[`(D)]₁ , ¼,[`(D)]_d\bar D_0 ,\bar D_1 , \ldots ,\bar D_d is called a Schur ring overG. It is known that such a partitionD ₀,D ₁,...,D _d can be used to construct an association scheme of classd. In this paper, we obtain a complete classification for the case whenG is cyclic andd = 3. The result corresponds to a complete classification of cyclic association schemes of class three.