By using the conventional observation data, NCEP reanalysis data, Nantong Doppler weather radar detection data and GR2 analyst, a EF2 tornado process occurred in Rudong county of Jiangsu province on 5 July 2016 was analyzed.The results show that the tornado occurred in the specific weather situation, which with strong instability energy, abundant moisture, strong vertical wind shear and low Lifting Condensation Level (LCL). When the sweep continuum cyclone, hook echo, and the strong echo area to the lower side of slope, the vertical profile has dome structure and bounded weak echo area, which is easiest to produce in the tornado hook echo. Hollow structure in GRanalyst three-dimensional display shows that the supercell here produced a strong vortex, which is conducive to the tornado; when the rotating speed in the symmetrical positive and negative areas continued to increase and develop downward, the low elevation detected the close speed, the strong mesocyclone also extends downward and appears rapid contraction, indicating a tornado occurrence and providing some indication for tornado forecasting.