A surveying system comprising: a total station and a target instrument, wherein said target instrument has a rod-like supporting member, and wherein a reflection sheet is wound around an entire circumference of said supporting member to define an object to be measured in the form of a linear reflection part, wherein said total station has a distance measuring light projecting unit for projecting a distance measuring light, a light receiving unit for receiving a reflected distance measuring light and producing a light receiving signal, a distance measuring unit (35, 36, 37) for performing a distance measurement of an object to be measured based on said light receiving signal, an optical axis deflector provided on a distance measuring optical axis and capable of deflecting said distance measuring optical axis two-dimensionally, a projecting direction detecting module for detecting a deflection angle of said distance measuring optical axis and performing an angle measurement, and an arithmetic control module for controlling a deflecting action of said optical axis deflector and a distance measuring action of said distance measuring unit, wherein said optical axis deflector comprises a pair of optical prisms (65a, 65b) rotatable around said distance measuring optical axis as a center and motors (72a, 72b) individually rotating said optical prisms independently, wherein said arithmetic control module is configured to control a rotating direction, a rotating speed and a rotation ratio of said pair of optical prisms and to control a deflection by said optical axis deflector and to two-dimensionally scan said distance measuring light passing through said optical axis deflector, and wherein said arithmetic control module is configured to perform a distance measurement and an angle measurement by two-dimensionally scanning said distance measuring light with respect to two or more points on which said distance measuring light crosses said object to be measured, and further to calculate three-dimensional coordinates of said two or more points based on results of the distance measurement and the angle measurement of said two or more points and to detect a tilt and a tilt direction of said target instrument based on said three-dimensional coordinates. wherein said target instrument has a rod-like supporting member, and wherein a reflection sheet is wound around an entire circumference of said supporting member to define an object to be measured in the form of a linear reflection part, wherein said total station has a distance measuring light projecting unit for projecting a distance measuring light, a light receiving unit for receiving a reflected distance measuring light and producing a light receiving signal, a distance measuring unit (35, 36, 37) for performing a distance measurement of an object to be measured based on said light receiving signal, an optical axis deflector provided on a distance measuring optical axis and capable of deflecting said distance measuring optical axis two-dimensionally, a projecting direction detecting module for detecting a deflection angle of said distance measuring optical axis and performing an angle measurement, and an arithmetic control module for controlling a deflecting action of said optical axis deflector and a distance measuring action of said distance measuring unit, wherein said optical axis deflector comprises a pair of optical prisms (65a, 65b) rotatable around said distance measuring optical axis as a center and motors (72a, 72b) individually rotating said optical prisms independently, wherein said arithmetic control module is configured to control a rotating direction, a rotating speed and a rotation ratio of said pair of optical prisms and to control a deflection by said optical axis deflector and to two-dimensionally scan said distance measuring light passing through said optical axis deflector, and wherein said arithmetic control module is configured to perform a distance measurement and an angle measurement by two-dimensionally scanning said distance measuring light with respect to two or more points on which said distance measuring light crosses said object to be measured, and further to calculate three-dimensional coordinates of said two or more points based on results of the distance measurement and the angle measurement of said two or more points and to detect a tilt and a tilt direction of said target instrument based on said three-dimensional coordinates.