Abstract: The possibility of a relationship between thunderstorm and cloud-to-ground(CG)lightning activity suggeststhat the real-time lightning data provided by local lightning detectors may be useful in the nowcasting of some severe local thunderstorms.In fact, in recent years, increased interest in severe storms associated with lightninghas been led to by such potential application and the desire to understand the cloud electrification mechanisms responsible for the lightning behavior.In the current study, bsaed on available data sources such as CG flashrecords, radar detection data and conventional sounding data, the CG lightning properties of thunderstorms inthe contiguous Guangzhou city and the influences of local environmental conditions are explored.Based on theweather reports and the lightning activities, 10 lightning storms and 10 non-lightning storms are selected and divided into two groups to identify the CG lightning properties and favorable environmental conditions.In additionto general statistical analysis, sounding data from the nearby Qingyuan station are analyzed to identify systematicdifferences in the local mesoscale environment of lighting and non-lightning storms.And two typical lightningstorms are investigated to study the lightning behavior in severe and non-severe thunderstorms.It shows that over 90% negative polarity cloud-to-ground(CG)lightning is produced by most thunderstorms around Guangzhou city.During a 3-hour period surrounding the most lightning activity and calculatedwithin an analysis range of 150 km, of the ten selected storms with lightning records, the largest storm-averageflash density is 0.13 km^-2·h^-1, the maximum mean negative current is 28.4 kA, the peak current of the firststroke is 183 kA, and the largest multiplicity(the number of strokes per flash)is 14.CG flash rates are foundto be associated with storm intensity.Within the same system, when the storm develops stronger, it tends toproduce higher CG flash rates.When compared among different storms, however, the CG flash rates are quitedifferent.Stronger(weaker)storm does not necessarily mean that it produces higher(lower)CG flash rates.Bystudy of the differences of local environmental conditions between the two groups of selected lightning and nonlightning storms, at least, it can be inferred that storms with CG flash phenomena are supported in environmentwith stronger vertical wind shear, higher storm-relative helicity and convective inhibition(CIN). CG flash isproved more likelihood to occur in stronger convective systems with more organized features.Analysis of typicalcases reveals that urban environment may have possible impact on the evolution of thunderstorms and subsequentlightning activity.It is found that when moving thunderstorm approaches the urban areas of Guangzhou, its intensity and CG flash rates tend to decrease, and after it travels through the city, thunderstorm intensity andflash rates increase again.Testing with more observational case studies is needed for this primary result, andmore studies are necessary before general assumptions can be made regarding the typical thunderstorm lightningbehavior in this local area.