  The inclination angle $\chi$ between magnetic and rotation axes of pulsars is
an important parameter in pulsar physics. The changes in the inclination angle
of a pulsar would lead to observable effects, such as changes in the pulse beam
width and braking index of the star. In this paper, we perform a short review
on the evolution of pulsar's magnetic inclination angle, as well as the latest
research progress. Using an alignment rotator model in vacuum, we investigate
the magnetic inclination angle change rates for 12 high-braking index pulsars
without glitch, whose timing observations are obtained using the Nanshan 25-m
Radio Telescope at Xinjiang Astronomical Observatory. For our purpose, three
representative pulsars J0157+6212, J1743-3150 and J1857+0526 are chosen and
their rotation and inclination angle evolutions are further investigated. In
the future, radio and X-ray polarimetric observations will provide more
information about the inclination angles of pulsars, which could help us
understand the origin of the variations in $\chi$ of pulsars and shed light on
the range of possibilities of pulsar magnetic field configuration. A continuous
study of the pulsar inclination angle will provide an important window into
additional physical processes at work in the young and highly magnetized
pulsars.
