Abstract: The perception and reaction to intense stimulations were. studied ontwo patients with insensitivity to pain (a girl and a boy at the age of10 and 13 respectively), with a control group of 20 normal children atthe same age stage. Results: (Ⅰ)Daily-life pain: Not detected in both patients (includingpain sensation and reaction). (Ⅱ) Experimental pain:1)pain sensation:Not detected in both patients, 2) "pain" reaction: case 1 had "pain"reaction similar to that of normal children. The changes in pulse, resp-iration and behavioral reactions were obvious. Case 2 had no "pain"reaction. The changes in pulse and respiration were slight and behavio-ral reaction was absent. It was different from normal children. It seems that congenital insensitivity to pain may be divided into twotypes: incomplete type (as case 1) and complete type (as case 2). Onecan have "pain" responses without pain-feeling. The results verify the two-component theory of pain from a specificaspect.

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