Abstract: The ballistic experiment of rubber bullets impacting the pigs was carried out to study the biological injury mechanism. The influences of velocity, hardness, and caliber of rubber bullet on creature injury effect are analyzed and characterized by trauma and behavior response. The experimental results indicate that trauma is mainly dominated by skin peeling, pale and blush. The visible discontinuity of skin injury exists between peeling zone and pale zone. The shear action of rubber bullet gives rise to peeling and pale, and synergistic effects of tensile and contraction of skin give rise to blush. Trauma degree is increasingly severe with the increase in impacting velocity of the same kind of rubber bullets impacting on creature thorax and abdomen, but the diameter of peeling is almost unchanged at different impact velocities. The single variable method is used to analyze the experimental results of rubber bullet impacting on creature thorax. It is indicated that the specific kinetic energy needing to cause visible trauma (skin peeling, pale or blush) follows as 70 HA Shore bullet＜45 HA Shore bullet＜20 HA Shore bullet, 32 calibre bullet ＜16 calibre bullet＜8 calibre bullet, which means that if Shore hardness and caliber are larger, the less specific kinetic energy needs in visible trauma inducement. And if the caliber is larger, the less specific kinetic energy needs in obvious abnormal behavior response (continuous scream, sudden jump or trying to escape) inducement. Moreover, the specific kinetic energy leading to 50% abnormal behavior risk is higher than that leading to 50% visible trauma risk. Key

Key words: rubberbullet, blunttrauma, specifickineticenergy, riskprobability, traumafeature, behaviorresponse