The stink bug Nezara viridula is a seriously harmful pest insect infested on many agricultural cropl and widely distributed in the world. the survey on N. viridula was conducted in four main argicultural crops, such as rice, maize, beans and sesame in Nghe An province, Vietnam from 2010-2011. The results showed that there are 10 morphological patterns (phenotype) of green bugs N. viridula appeared in the cultivated area, namely G, O, F, R, OR, GO, OG, Y, B and C, of those the morphological patterns G and O were commonly observed on maize, rice and sesame crops. In 2010 spring, the morphological patterns of G and O were observed possitively correlated with the density of green bugs on maize (R = 0.76) and negatively correlated with the density of green bugs on spring rice (R = -0.87). In 2011 spring, the G pattern was observed negatively correlated with the density of green bugs on maize (R = -0.62) and the morphological pattern G was weakly correlated with the density of green bugs on sesame (R = 0.34).