With broadband femtosecond (fs) laser as the excitation source, two-photon fluorescence (TPF) imaging system is built. Under broadband excitation of fs pulses, TPF spectrum of Rhodamine B solution is measured and TPF microscopy is performed with solid Rhodamine B samples. In the TPF microscopy of solid Rhodamine B sample, relationship between TPF intensity and power of the excitation pulses is analyzed. Besides, TPF intensity is modulated through adjusting polarizationSdirection of the linearly polarized exciting field with a half wave plate and sine-like modulation of TPF intensity is realized.