We studied electron resonant tunneling and Coulomb blockade in nanocrystalline Si (nc-Si) with double SiO2 barriers, which is fabricated in-situ in a plasma enhanced chemical vapor deposition system. In capacitance-voltage measurements, discrete capacitance peaks due to electron resonant tunneling into energy levels of nc-Si dots and Coulomb blockade charging in nc-Si dots have been observed at room temperature. For smaller dots, capacitance peaks are more distinct due to the stronger Coulomb blockade effect. Meanwhile, conductance plateau in the region of capacitance peaks are also observed due to the charging effect in nc-Si dots. Experimental results are in agreement with theoretical evaluation based on the model of Coulomb blockade.