Method and apparatus for determining angular and transversal displacements of a shield machine and a succeeding pipe relative to a pre-determined schedule central axis of a tunnel to be constructed by pipe-jacking tunneling which includes providing on the shield machine a first light emitter which emits rearwardly a light beam along the central longitudinal axis of the shield machine and a reference position on the axis of the shield machine, projecting the light beam to a pair of targets, each having a scale and being provided in a succeeding pipe spaced from each other by a predetermined distance along the central longitudinal axis of the succeeding pipe to form light spots on the targets, projecting to the pair of targets a light beam emitted from a second light emitter along the scheduled central axis of the tunnel to be constructed to form further light spots on the targets with the second light emitter being located at the rear portion of the tunnel, and reading the light spots and the further light spots on each of the targets on the respective scales and measuring a distance from the reference position to one of the targets to determine the angular and transversal displacements of the shield machine and the succeeding pipe relative to the scheduled central axis of the tunnel to be constructed. Certain calculation formulas are presented. The targets can be pivotally mounted in the succeeding pipe to pivot away from or into the paths of the light beams. Each target can be a semi-transparent plate on which the scale is marked.