A stand for medical optical instrument capable of easily extending, adjusting easily a counter balancing according to a change of a weight of medical optical instrument such as microscope, as well as, maintaining stably a counter balancing regardless of a position of medical optical instrument. The stand for medical optical instrument includes: a carrier arm including a first to fourth links having a first to fourth turning joins, wherein the first to fourth links are rotatably coupled to each other in a parallelogram shape and the second turning joint is rotatably coupled to a holding unit, and a front link extended from the fourth link； and a counter balancing unit coupled to the first and second links, wherein the counter balancing unit is rotated in connection with the first and second links on the second turning joint according to the rotation of the carrier arm, and capable of maintaining a counter balancing of the carrier arm by compensating a torque generated in the second turning joint by a medical optical instrument installed on the front link.
