Highly conductive and transparent In4Sn3O12 films have been prepared by DC magnetron sputtering using In2O3-SnO2 targets with a Sn content (Sn/(Sn + In) atomic ratio) of 45-55 atomic %. In4Sn3O12 films with a low resistivity on the order of 10(-4) Omega cm were prepared in the substrate temperature range of room temperature (RT) to 350 degrees C, at a sputter pressure of 0.2 Pa with an O-2 gas content of 4%. The obtained resistivity decreased gradually as the film thickness was increased from 20 to 300 nm. In4Sn3O12 films prepared on substrates at RT exhibited a spatial resistivity distribution on their surface which was strongly dependent on the O-2 gas content. The spatial resistivity distribution was mainly related to the amount of oxygen gas available locally at locations on the substrate. A resistivity of 2 x 10(-4) Omega cm and an average transmittance above 80% in the visible range were obtained for films prepared at a substrate temperature of 350 degrees C. A carrier concentration on the order of 10(21) cm(-3) and a Hall mobility as high as 20 cm(2) V-1 s(-1) were obtained in the In4Sn3O12 films.