An intravenous flow control device includes a rigid casing (2) defining a flow passage having a fluid entrance (211) and a fluid exit (222) and a flow regulator (1) disposed in the casing (2) and including a floating member (11) having a hollow cylinder (111), an opening (112) on a bottom of the hollow cylinder (111), and a lower stepped-diameter chamber (113) in the hollow cylinder (111) and communicating with the opening (112) and a valve member (12) including a hollow member (121), a flat member (122), and a space (123) open to top. The valve member (12) is retained in the chamber (113) through the opening (112) and together they form a sealed hollow structure. The flow regulator (1) floats on fluid in the casing (2) due to the sealed hollow structure.
