Abstract: The data from Optical Transient Detector (OTD) and Lightning Imaging Sensor (LIS),with the other metcorological data, have been used to investigate the characteristics of lightning activity in the typical marine mainland region (11. 25°S 3. 75°N, 96. 25°-128. 75°E) during the El Niño (1998 spring) and during the La Nina (1999 spring). This study analyzes the impact of the number of the thunderstorm cells and the thunderstorm cell flash rate on lightning variation,and discusses the reason of lightning variation by comparing the atmospheric circulation,relative humidity, the maximum connective available potential energy and connective storm height between the El Niño spring and the La Nina spring. The results show that,(1) in 1998 spring, the number of lightning and thunderstorm cells is more than that in 1999 spring; and the tonal mean and meridional mean of thunderstorm cell numbers and lightning numbers show that there exists a trend of the lightning and thunderstorm activity being to the cast and the south;(2) in the typical marine mainland region,changes in the number of thunderstorm cells are the major factors of lightning variation,and the thunderstorm cell flash rate is the secondary factors of lightning variation; and (3) compared with the spring of 1999,in 1998 spring the subtropical high’s scope is bigger while the intensity is stronger; the relative humidity at the ground is bigger than that in the upper levels with a bigger difference of relative humidity between low and high levels, which is conducive to the development of convection;and,at the same time, the connective storm height is higher and the layer of ice phase particles is thicker with an exuberant convection development where the thunderstorm activity closely related with the CAPE value since the space distribution of the number of the days with the maximum CAPE greater than 300 J/kg is similar with that of the lightning density as well as the thunderstorm cell density.