  In this paper, we are discussing the effect of the use of magnetic compasses
on the orientation of ancient Chinese architectonical complexes. As Czech
researchers proposed in 2011, assuming these complexes ideally oriented by the
ancient architects along north-south direction, in the case that the surveys
were made by means of magnetic compasses, we can find the axes of the complexes
deviating from the cardinal direction, according to the local magnetic
declination that existed at the time the structures were built. Following this
idea, here we discuss some examples of possible alignments obtained by means of
magnetic compasses, concluding that the Chinese surveyors adopted, during the
Ming dynasty, a method based on the magnetic compasses. The architects of the
antecedent Yuan Dynasty probably used an astronomical method.
