NOVELTY - System comprises a disinfection processing unit (10) for removing microorganisms which inhibit growth of microalgae in wastewater; a flow control unit (20) for adjusting the concentration of organic contaminants in wastewater passing through the disinfection processing unit; a microalgae culture injection unit (30) for injecting the culture for growing microalgae passing through the flow control unit; a microalgae culture device (100) to culture proliferative microalgae; and a biomass production unit (40) for concentrating, purifying and producing biofuels.    USE - The system is useful for culturing microalgae (claimed).    ADVANTAGE - The system produces microalgae of high intensity by increasing intensity of light; controls growth rate and circulation speed; and is economical.    DETAILED DESCRIPTION - System comprises a disinfection processing unit (10) for removing microorganisms which inhibit growth of microalgae in wastewater while inflowing wastewater including aeration tank influent of a sewage treatment plant or a effluent of livestock raw sewage treatment plant; a flow control unit (20) for adjusting the concentration of organic contaminants in wastewater passing through the disinfection processing unit to fit growth environment of microalgae; a microalgae culture injection unit (30) for injecting the culture for growing microalgae passing through the flow control unit; a microalgae culture device (100) to culture proliferative microalgae by using the wastewater passing through the microalgae culture injection unit; and a biomass production unit (40) for concentrating, purifying and producing biofuels including biodiesel or bioethanol from high density microalgae cultured from the microalgae culture device, where the microalgae culture device comprises an advanced raceway pond opened on the upper side provided with the certain width, certain length and certain height and formed with linear type barrier shaped baffle in longitudinal direction of plane to elliptical shaped main body to cultivate mass culture of high density microalgae, and a reactor comprising at least one paddle for circulating the culture medium at a constant speed and driven automatically or manually such that the speed of circulation is controlled according to the growth rate of the microalgae. An INDEPENDENT CLAIM is also included for culturing microalgae, comprising (a) removing microorganisms which inhibit growth of microalgae in wastewater while inflowing wastewater including aeration tank influent of a sewage treatment plant or a effluent of livestock raw sewage treatment plant by the disinfection processing unit, (b) adjusting the concentration of organic contaminants in wastewater passing through the disinfection processing unit to fit in the growth environment of microalgae by the flow control unit, (c) injecting the culture for growing microalgae passing through the flow control unit by the culture medium injection unit, (d) proliferative culturing of microalgae by using the wastewater passing through the microalgae culture injection unit, (e) concentrating, purifying and producing biofuels including biodiesel or bioethanol from high density microalgae cultured from the microalgae culture device, where the growth culture in the step (d) is primarily proliferated until the concentration of microalgae in culture medium reaches to the cultivable level in the reactor provided with the miniature reactors installed separately inside the reactor of the microalgae culture device.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the system for culturing microalgae (Drawing includes non-English language text).    Disinfection processing unit (10)    Flow control unit (20)    Culture medium injection unit (30)    Biomass production unit (40)    Microalgae culture device (100)