Using the radar and automatic weather station (AWS) data, and the Tianjin corrected sounding data, the rules and synoptic scale meteorological conditions for three types of thunderstorms initiation and intensification associated with sea breeze fronts in the Bohai Bay from 2004 to 2009 are investigated. Based on VDRAS (variational Doppler radar analysis system) data, the thermal and dynamical structures of the third type thunderstorm were analyzed. The results show that： (1) Under the strong instable environment, thunderstorm is initiated and intensified when it moves along the sea breeze fronts. (2) The location, the rate of intensification, and the intensity are distinct for different types. (3) For type Ⅰ〖KG-*4〗, the dynamical is better than the other two types, and convection weather is stronger. For type Ⅲ〖KG-*7〗, the thermal, dynamical and vapour are better than the other two types, while CIN (convection inhibition) is small. (4) A mesoscale convergence line is formed at low level by sea breeze front. Vertical updrafts along the sea breeze front extend from the ground to the height of 3 km. Strong centers appear at the height of 1.5-3.0 km, and the maximum velocity is up to 1.9 m·s-1.