The people have conducted the massive research with the ESR method to in the rough diamond and the artificial diamond nitrogen impurity, and has obtained many useful results, for example: Along with contains the nitrogen quantity the increase, artificial diamond the ESR spectral line, broadens, the central peak gradually increases, but the sideline slowly reduces, after contains the nitrogen quantity to outdo the certain degree the sideline to vanish, contains the nitrogen quantity to increase along with the crystal grain size reduces, with the diamond unit crystal survey, observed the diamond essence magnetic moment the function; In diamond ferro magnetic contains the object, the matter existence, is affecting the absorption peak width; Also some people proposed the diamond magnetic size has the certain relations with the compressive strength. This article mainly is the inspection makes the catalyst synthesis with the cobalt the diamond ESR spectrum with his magnetization relations, and discussed the nitrogen impurity in diamond existence form according to the ESR spectrum some characteristic quantities, the research result included: 1. Atificial diamond magnetism Diamond obtains which by the identical synthesis, as a result of the synthesis cavity internal pressure, the temperature distribution non-uniformity, the diamond interior which synthesizes includes the ferromagnetic matter (catalyst alloy) the quantity difference to be very big. 2.Atificial diamond ESR spectral line In arrives between the nitrogen content, the ESR spectrum fine structure resolution elevates along with the nitrogen content drops. 3. Atificial diamond compressive strength The compressive strength along with contains the nitrogen quantity the increase to reduce.