Rhagium inquisitor (Coleoptera: Cerambycidae), which contributes to the process of decay by digesting the cambium layers of old trees in ecosystem, is detrimental on timbers. The beetle is resistant to stress condition although sensitive to environmental changes. Morphological differences in size of R. inquisitor collected from East of Marmara Basin were investigated between female-male, humid subtropical climate (CFA)-hot summer Mediterranean climate (CSA) and industry-forest zones. Multivariate analysis of variance was carried out on 41 morphological traits. Discriminant analysis and principal component analysis were conducted then.