A membrane filtration system and a membrane bio reactor including the same are described. In an example, the membrane filtration system includes: a treatment tank; a membrane support frame disposed in the treatment tank and mounted with a separation membrane; a separation membrane module mounted on the membrane support frame; a vane member disposed at a lower end of the membrane support frame and provided to lift sludge accumulated at a lower part of the treatment tank; and a reciprocating portion connected to the membrane support frame and reciprocating the membrane support frame, in which the separation membrane module includes an upper frame and a lower frame and a hollow fiber membrane installed between the upper frame and the lower frame.