This paper describes on nonlinear modeling and bifurcation phenomena in switched power-factor-correction (PFC) boost regulator whose switching borders are varying periodically with time. The mathematical modeling is done by nonlinear differential equations. The system dynamics of this switching circuit can be represented by one-dimensional (1-D) piecewise smooth maps under discrete modeling. In particular, the dynamical behavior of the current-mode-controlled PFC boost circuit is investigated from bifurcations viewpoint. The control of bifurcations is also studied in this paper by varying system parameters.