Understanding　the　mechanism　of　functional　connectivity　in　neural　system　is　of　great　benefit　to　lot　of　researches　and　applications.　Microfluidics　and　microelectrode　arrays　(MEAs)　have　been　frequently　utilized　for　in　vitro　neural　cultures　study.　However,　there　are　few　studies　on　the　functional　connectivity　of　neural　cultures　grown　on　a　microfluidic　chip.　It　is　intriguing　to　unveil　the　influences　of　microfluidic　structures　on　in　vitro　neuronal　networks　from　the　perspective　of　functional　connectivity.　Hence,　in　the　present　study,　a　device　was　established,　which　comprised　a　microfluidic　chamber　for　cell　growth　and　a　MEA　substrate　for　recording　the　electrophysiological　response　of　the　neuronal　networks.　The　network　topology,　neural　firing　rate,　neural　bursting　rate　and　network　burst　frequency　were　adopted　as　representative　characteristics　for　neuronal　networks　analysis.　Functional　connectivity　was　estimated　by　means　of　cross-covariance　analysis　and　graph　theory.　The　results　demonstrated　that　the　functional　connectivity　of　the　in　vitro　neuronal　networks　formed　in　the　microchannel　has　been　apparently　reinforced,　corresponding　to　improve　neuronal　network　density　and　increased　small-worldness.