A trocar system for use in laparoscopic surgery is disclosed. According to an embodiment of the present invention, the trocar system includes: an upper housing having a circular or oval shape with a lower opening a plurality of protrusion membranes provided to the upper housing to install a trocar one or more tubes for sustaining air passage installed on the upper housing and a lower guide formed at the lower edge of the upper housing, installed on the upper portion of a laparoscopic retractor, and conveniently removed therefrom. The trocar is fixedly installed on the protrusion membrane, and includes: a trocar body having a cylindrical shape a valve cover disposed over the trocar body to close the upper space thereof a recess for an installation ring disposed on the lower outer circumference of the trocar body and an elastic press which is moved in conjunction with the side portion of an upper valve to open the upper valve the trocar system further includes a seal part. When the trocar body is inserted into the protrusion membrane, the seal part is disposed at the recess for an installation ring to fix the outer circumference of the protrusion membrane.
