This study has conducted to investigate the effect of air pollution on diagnostic elements and morphologicl characters of leaves of Neruim oleander Cultivated in roadsides in Lattakia City . Samples were collected from tow sites differ in pollution
inteusity between october 2012 and september 2013 .
The first site ( Al Jmhoria street in Lattakia city ) was more polluted and has more traffic activity .
Whil the second site ( tishreen University park )
Was Less polluted and less traffic activity .
The results have showed that the length , the weight and the colour of the leaf are negtively incieased because of traffic intensity and this , inturn , affects the shape , the size and the number of diagnostic elements which play animportant rule in differentation the species from each other .
