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Let $R$ be a finite commutative ring with identity and $Z(R)$ denote the set of all zero-divisors of $R$. Note that $R$ is uniquely expressible as a direct sum of local rings $R_i$ ($1\leq i\leq m$) for some $m\geq 1$. In this paper, we investigate the relationship between the prime factorizations $|Z(R)|={p_1}^{k_1}\cdots {p_n}^{k_n}$ and the summands $R_i$. It is shown that for each $i$, $|Z(R_i)|={p_j}^{t_j}$ for some $1\leq j\leq n$ and $0\leq t_j\leq k_j$. In particular, rings $R$ with $|Z(R)|=p^k$ where $1\leq k\leq 7$, are characterized. Moreover, the structure and classification up to isomorphism of all
commutative rings $R$ with $|Z(R)|={p_1}^{k_1}\ldots {p_n}^{k_n}$,
where $n\in \Bbb{N}$, $p_i^,s$ are distinct prime numbers, $1\leq k_i\leq 3$ and nonlocal commutative rings $R$ with $|Z(R)|=p^k$ where $ k=4$ or $5$, are determined.
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