The present invention relates to the field of communications technology, and in particular, to technology related to impedance matching in communication technology, and in particular, to a dielectric phase shifting unit, dielectric phase shifter and base station antenna. It includes a feeding network and a dielectric plate for impedance matching and for moving along a predetermined path, an impedance matching portion of the dielectric plate being disposed on one end of the dielectric plate adjacent to an input port on the feeding network. The present invention not only reduces the number of impedance matching and network loss; it also reduces the equivalent electrical length of the entire network, effectively saving costs, reducing the complexity of disassembly and assembly of related components, and improves disassembly and assembly efficiency.