Gate oxide shorts (GOS) defect is a critical factor in influencing yield or reliability of the wafer. Due to the conventional test vehicles are not appropriate to collect mass of testing data for GOS defect densities detection and have different manufacture process from the normal transistors resulting in the high testing cost. In this paper, a novel pseudo transistor matrix (PTM) is proposed for GOS density extraction which has almost the same structure as normal transistor. By assuming that GOS are completely independent, the defect density of GOS is extracted from the layout attributes and yield with PTM as a test vehicle to collect mass of testing data. Experimental results show that the extracted GOS defect density is in a good agreement with inline e-test data.