Abstract: A permanent magnet wax proof device includes one or more than one magnetic pole pairs, each of which includes two magnetic circuit units, each said unit comprises radially oriented magnets cooperating with axially or circumferentially oriented magnets or both, resulting in high concentration of magnetic field in oil flow so as to effectively decrease oil viscosity and suppress the process of wax accumulation on the wall of an oil pipe in an oil well or pipelines for conveying oil. This invention provides embodiments which can be connected to oil pipes and sucker rods respectively. This device consumes no power.