This study examined the influences of product knowledge(subject knowledge, purchase experience and information search) on perceived risks and benefits to natural dyeing product. Data were collected from a total of 213 Korean females ranging from 20 to 50 years old who know natural dyeing product through online survey. There were significant differences between(or among) groups with different levels of subject knowledge, purchase experience and information search in several types of perceived risks and benefits to natural dyeing product. Consumers with high knowledge of natural dyeing product perceived several types of risks lower than consumers with low knowledge but they perceived several types of benefits higher than consumers with low knowledge.