The fractional matching preclusion number of a graph G, denoted by fmp(G), is the minimum number of edges whose deletion results in a graph with no fractional perfect matchings. Let Gk,n\documentclass[12pt]{minimal}
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\begin{document}$$G_{k,n}$$\end{document} be the complete n-balanced k-partite graph, whose vertex set can be partitioned into k parts, each has n vertices and whose edge set contains all edges between two distinct parts. In this paper, we prove that if k=3\documentclass[12pt]{minimal}
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\begin{document}$$k=3$$\end{document} or 5 and n=1\documentclass[12pt]{minimal}
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\begin{document}$$n=1$$\end{document}, then fmp(Gk,n)=δ(Gk,n)-1\documentclass[12pt]{minimal}
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\begin{document}$$fmp(G_{k,n})=\delta (G_{k,n})-1$$\end{document}; otherwise fmp(Gk,n)=δ(Gk,n)\documentclass[12pt]{minimal}
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\begin{document}$$fmp(G_{k,n})=\delta (G_{k,n})$$\end{document}.