In this paper, we introduce the Y-compactness in L-fuzzy topological spaces. It possesses the following properties: (1) Y-compactness is hereditary for Y-closed subsets, (2) Y-compactness is preserved under Y-irresolute mapping. (3) Every set with finite support is Y-compactness. The Y-compactness is defined for arbitrary L-fuzzy subsets. It is described with α-net, α-filter, r-Y-cover form and r ⁺-finite intersection property.