By using the sounding data, surface wind vector, sounding data, NCEP d ata and the boundary convergence line detected by Jinan Doppler weather radar, s evere convective storms happened in Shandong province during 2005-2007 were anal yzed. The results show that Doppler weather radar with high spatial and time res olution can obtain the information of boundary convergence zone. Normally, the n arrow band echo reflects the existence of thunderstorm outflow and surface wind field convergence zone. The outflow boundary keeps away from storms or the con vergence zone moved in the same direction because the surface wind can't trigger convective storm in a condition of weak thermal instability. The coalescen t of two outflow boundary or the coalescent of the outflow boundary and the surf ace wind convergence zone can trigger local severeconvective storms, whereas the single surface wind convergence zone can produce isolated convective storms. The se results can afford a pivotal reference for short range forecasting and convec tive storm nowcasting. The difficulties in nowcasting convective storms are the incertitude of initial echo location, the formative time of initial echo and the type of convective storms.