A system and a method for detecting a defect, capable of extracting a defect occurring depending on finishing accuracy required for circuit operation are provided. The system includes a timing analyzer for extracting a critical path in which a high accuracy is required for a signal transmission operation as compared with other portions based on circuit design data, a critical path extractor for comparing the circuit design data with layout design data on a pattern and for extracting graphical data including the critical path extracted by the timing analyzer, an inspection recipe creator for deciding a portion to be inspected, based on coordinate information on the graphical data including the critical path extracted by the critical path extractor, and an SEM defect review apparatus for acquiring an image of the decided portion to be inspected on a wafer according to an inspection recipe created by the inspection recipe creator.