To further investigate the distribution characteristics of lightning parameters with altitude

and provide references for the design of lightning protection engineering and lightning risk assessment

the parameters such as frequency

polarity

amplitude of lightning current and gradient of wave front at different altitudes were analyzed by a mathematical statistics method based on the data monitored by lightning location system（LLS） in Hubei province from January 2007 to December 2017. The results show that the frequency of negative cloud-to-ground（CG） lightning and total CG lightning decreases linearly with increasing height

the frequency of CG lightning at the altitude of 2 700 m is about 1/3 that at 300 m

and the frequency of positive CG lightning roughly presents a trend of "V shape" with altitude

and a relative minimum occurs at the altitude of 800 m. At the altitude of 800～2 700 m

the proportion of positive CG lightning increases significantly with altitude

and the positive CG lightning ratio at 2 700 m is about 3.7 times that at 800 m. The amplitude of negative CG lightning and total CG lightning median current present a trend of roughly "V shape" with altitude

and when the altitude is 1 500 m

negative CG lightning and total CG lightning median current amplitude are relatively minimal. In the high mountains with altitude of 1 200～1 700 m

negative CG lightning and total CG lightning less than or equal to 20 kA have a higher proportion of the current amplitude

which is more than twice the altitude of 200 m. Over 1 500 m above sea level

the average ratio of lightning current amplitude larger than that of 100 kA is greater than that of low hill and plain area. The average gradient of wave front for positive CG lightning

negative CG lightning and total CG lightning decreases with natural logarithm as the height increases. According to the above research

the probability of counter attack caused by the large lightning current in the middle and high mountain areas above 1 500 m is higher than that in the hills and plains

while in the high mountain area of 1 200～1 700 m

the small lightning current is relatively high. Compared with the middle and high mountains

the lightning electromagnetic induction in the low hills and plains are relatively harmful.