Abstract: A new method of oxygen enrichment from air by use of gradient magnetic fields was introduced, A magnetic space with open borders was formed by two opposite magnetic poles of two permanent magnets with certain distance, A field intensity gradient, which points at the interior of the magnetic space, existed near the borders. When oxygen molecules in air outflowed via the borders, they would be fettered by the magnetizing force. So oxygen was enriched in the magnetic space, especially at the far end away from the air inlet, The most outstanding characteristic of this method was to be able to effectively avoid the re-mixing caused by gas turbulence, Brown motion and diffusion. Neodymium-iron-boron permanent magnets were adopted and the size was 78 mm×38 mm×30 mm. The size of the formed magnetic space was 78 mm×38 mm×1 mm, The experimental results showed that the highest oxygen volume fraction in the magnetic space appeared at the farthest border apart from the air inlet. The airflow ratio of inlet to outlet had an optimal value(air inlet ≤ 60 mL·min^-1) which made the highest oxygen volume fraction. Under the experimental conditions in this study, it should be about 2.0, When the airflows of inlet and outlet were up to 40 mL·min^-1 and 20 mL·min^-1, respectively, the increment of oxygen volume fraction at the outlet reached 0. 65%.