Provided are an apparatus for injecting a liquid into a primo-node and a primo-vascular system tracing system including the apparatus. The apparatus includes a liquid injection tube to inject a liquid into a primo-node of an object, and a suction tube to hold the primo-node to inject the liquid injection tube into the primo-node. The liquid injection tube and the suction tube are formed as one body. The liquid injection tube is inserted into an inner side of the suction tube and an edge unit of the liquid injection tube protrudes to the outside from an inner side of a suction opening of the suction tube.