A periodic magnetic field (PMF) of B=B-0 sin omega t, where B-0=106 Guass and omega=40,000 rpm, was designed and first applied in a special hot-filament chemical vapor deposition (HFCVD) system for diamond synthesis. Different to the conventional HFCVD, an external PMF was introduced for diamond thin film deposition on a Si (111) substrate. The morphology and cross-section of the film were analyzed by field emission scanning electron microscopy (FESEM) while the bond structure was investigated using Raman spectroscopy. Compared with the conventional HFCVD, the growth rate of diamond film defined as the ratio of film thickness vs deposition time increases by about 7 times at 520 degrees C with PMF. The I-Dia/I-G ratio in Raman spectra indicates that the quality of the diamond film grown with PMF is much higher than that of the film grown by conventional HFCVD. The research shows that the novel technology using PMF may have great practical application potentiality in CVD diamond growth at low temperature and in some relevant fields. (C) 2009 Elsevier B.V. All rights reserved.