The tight focusing properties of the femtosecond radially polarized light was analyzed on experimental setup, which including a femtosecond laser source and focal spot recording setup. According to the numerical simulation, in the case of being focused with the objective lens of NA=0.9, the linearly polarized light with the wavelength of 750 nm can get its smallest focal spot with FWHM of 1.3 μm, while that of the radially polarized light is 1.0 μm. The holographic plates were used as the recording media to record and measure the tiny focal spots, which were placed on a electric power-driven precise translation stage with precision of tens of nonameters so as to obtain the exactly minimum focal spots for the measurements by precise step-scan. The measurement result indicated that the radially polarized light can achieve sharper and tinier focal spots than the lineraly polarized light when with high NA focussing lens, whose FWHMs are 4.6 μm and 2.9 μm respectively for the same cases as the somulations.