An instillator for injection of a Ringers solution temporarily stores Ringers solutions or others, and couples a precise flow regulator onto an instillation container, thereby allowing the solutions to be administered more accurately, preventing accidents from happening because the regulator is out of a patients reach, and allowing a connected tube to be easily arranged. The instillator includes an instillation container, a solution inflow tube with a penetration needle and a solution guide passage, and a lower stopper with a solution drainage passage and a tube connector, wherein a drainage guide plate with a drainage hole is inserted into the container to discharge a solution downwardly, a precise flow regulator is coupled onto the plate to be rotated from side to side, and an instillation hole communicating with the tube connector is formed in the regulator.
