The purpose of this paper is to describe the difference between the meaning and usage of the synonyms KIKEN and RISUKU through a survey using corpus. 1.KIKEN and RISUKU have a common meaning of 'the possibility of undesirable events or negative consequences'. 2.In the case of complex nouns KIKEN represents prediction and prevention of dangerous areas, places, substances, people, actions, or risks, whereas RISUKU represents management and evaluation of risks. 3.In the case of receiving the formula of a NO noun, KIKEN represents a risk of body, life, or disaster, whereas RISUKU related to economic activities. 4.In the case of receiving a basic verb modification, KIKEN indicates the risk of making a mistake, an incident, an accident, etc., whereas RISUKU economic loss. 5.RISUKU tends to represent a risk to be borne, suppressed, managed, whereas KIKEN is detected, predicted, avoided.