With the increasing popularity of acupuncture therapy in the world, the safety of acupuncture has attracted more attention. The objective and impartial assessment of the safety of acupuncture becomes very important. The "adverse events of acupuncture" and "adverse reactions of acupuncture" are the common concepts in the research of acupuncture safety. In the paper, on the basis of the conceptual characteristics of "adverse events" and "adverse reactions" and in combination with the particular characteristics of acupuncture itself, the connation and features of the concepts of the "adverse events of acupuncture" and "adverse reactions of acupuncture" are analyzed. The interaction and differences are summarized. Both "adverse events of acupuncture" and "adverse reactions of acupuncture" are in the category of adverse medical events. The "adverse events of acupuncture" includes the damages induced by acupuncture therapy and also those without relationship with acupuncture therapy. The "adverse reactions of acupuncture" refers to the adverse outcomes induced by acupuncture therapy specially. It has the definite relationship with acupuncture therapy. Hence, the application of "adverse reactions of acupuncture" is more objective and accurate in the assessment of acupuncture safety.