The hourly surface AWS data, conventional suface and radiosonde observation data and NCEP-FNL reanalysis data over the period of 2008−2018 were used for analyzing the cyclonic gale processes in the Bohai Sea and the Yellow Sea. The cyclone deepening rate and the pressure gradient were also discussed to analyze the relationship between themeteorological factors and the strength of the cyclone. Based on the Petterssen equation of the surface cyclone development, the effects of temperature advection, vorticity advection and diabatic heating in cyclone development were discussed. The results show: (1) 70.5% of the cyclones were strengthened after entering the sea, 14.7% of them became explosive cyclones, 17.6% of them were invariant, and 11.7% of them weakened. The extratropical cyclones which caused strong winds in the Yellow Sea and the Bohai Sea mainly occurred in autumn, secondly in spring and winter, and hardly appeared in summer. The enter sea cyclones were developed on the leftside of the exit of upper-level jet stream or the diverging region, and weakened on the right side of the exit of upper-level jet stream. (2) There are three kinds of cyclones which have effects on the Yellow Sea and the Bohai Sea: the Mongolian cyclones (17.6%) which moved from the northwest to the southeast; the Yellow River cyclones (49%) moved from the west to the east, the Changjiang-Huaihe cyclones (33.4%) moved from the southwest to the northeast which tend to develop into explosive cyclones in autumn. The maximum wind speed region often appears in the northwest (or the west) quadrant of the cyclone in the autumn and winter season, and the maximum wind speed region appears in the southeast quadrant of the cyclone in the spring. (3) The correlation coefficient of the temperature advection and cyclone deepening rate is higher than that of vorticity advection and adiabatic heating. The correlation coefficient temperature advection and cyclone deepening rate, vorticity advection and cyclone deepening rate are greater than the correlation coefficient of the barometric gradient and cyclone deepening rate. The temperature advection and vorticity advection in the four analyzed explosive cyclones events were stronger than in other cyclones events. The correlation of diabatic heating and the barometric gradient is stronger than it with the cyclone variation rate. (4) The temperature advection and diabatic heating have important effects on the Huang-huai and Jianghuai cyclone. The effects from the vorticity advection on the Yellow River cyclone are more important, and the effects from the vorticity advection and diabatic heat-ingon the Mongolian cyclone are the least.