We propose two types of light pipes, namely wedge and circular forms, the incident direction of light propagation could
be rotated as necessary while still preserving beam polarization. We also deduce the basic conditions of these
preservations of polarization. Several typical cases of light pipes are analyzed by numerical simulation. As one of the
examples, it is verified that a collimated beam with +45 degree linearly polarization can be guided to any pre-settled
direction where the ellipse ratio variation in polarization is less than 0.1%.