In neurosurgical anesthesia, propofol based total intravenous anesthesia (TIVA) is frequently used due to brain relaxation and less effect on electrophysiologic monitoring. Response to propofol can vary between individuals and be associated with clinical factors including age and weight, and genetic polymorphism. Because the importance of rapid recovery in neurosurgery with long operation time is emphasized recently, the choice and dose adjustment of anesthetics should be determined according to clinical and genetic factors. Recently, researches about genetic variations have been performed with single nucleotide polymorphism (SNP). The aim of this study is to determine SNPs associated with propofol recovery and response in Korean adult population undergoing propofol based TIVA for clipping of unruptured cerebral aneurysm.