The aim of this study is to investigate the influence of structural defects on the mechanical properties of single-walled carbon nanotubes. During the growth process and functionalization of carbon nanotubes (CNTs), the Carbon-Carbon bonds in their nano-structure are broken. To evaluate the influence of this defect on the Young’s modulus of CNT, the number of broken C-C bonds, distribution and their arrangements in the nano-structure of CNT are all treated as random parameters. In this study, the finite element model of the CNT is built using nanoscale continuum mechanics approach and then structural defects are applied randomly. The Young's modulus of two defect types, known as Stone - Wales and Vacancy are investigated. The results reveal that the influence of Stone – Wales defect on the Young’s modulus of CNT is much less than that of Vacancy one. Moreover, a linear decrease in Young's modulus with respect to the increase in defect density is observed. In contrast to the available researchers in open literature, three parameters consisting of the number, distribution and arrangement of defects are modeled on the basis of full stochastic simulation.