A new significant solar energetic particle event was recorded by the ground level neutron monitor network during the descending phase of the 23rd solar cycle. This ground level enhancement event (GLE 70) occurred on 13 December, 2006 during a magnetically disturbed period manifested by a series of Forbush decreases of the cosmic ray intensity at neutron monitors, starting from 6 December, 2006. In the same period a series of significant X-ray flares occurred. The flare X3.4/4B in the AR10930 resulted in a big proton flux increase in the energy range above 100MeV according to GOES-11 satellite recorded. The worldwide network of neutron monitors recorded GLE 70 on 13 December, 2006 starting from about 2:48 UT. Recorded data of the neutron monitor network showed this enhancement is one of the greatest GLEs of the 23rd solar cycle. In this work data of several neutron monitor stations were chose to analyze for the event of 13 December, 2006, and some preliminary results are presented.