Tapered chirped fiber grating filter is analyzed from the detailed theoretical and experimental studies. The transmission spectrum of tapered chirped fiber grating filter is influenced by the parameters and loss of chirped fiber grating (length, refractive index modulation, chirp coefficient) and taper after examined by the transfer matrix method and resonance theory combined with coupled-mode theory. We study the influence of the chirped fiber grating wavelength reflectivity by tapering, and make the corresponding numerical simulation and experimental verification based on the above theories. Numerical simulation result is consistent with the experimental data.