Abstract: In order to simplify the calculation of structural system reliability, the dependence of RC Non-coupled shear walls were studied by using Monte-Carlo method under minor earthquakes in this article. The study results indicats that the failures of different storeys of RC holistic shear walls are neither absolutely independent nor absolutely dependent. The failures of the lower storeys (approximately accounting for half of the total storeys) are independent. The failures of the top storeys (approximately accounting for half of the total storeys) are dependent.