<正> The soft tissue wounds on the hind limbs of 21 dogs were inflicted bysquare fragments（0.35g in weight）which were shot with a smooth-bore testinggun.The impact velocities were 700-1500 m/s.Debridement and grossexamination were carried out 6 hours after injury.The main conclusions were asfollows:1.The primary wound track in the high velocity group looked like a funnel inshape.The part of the wound cavity near the entrance was the largest indiameter.2.The severity of tissue damage depended on the impact velocity.The higherthe velocity

the larger the wound cavity.3.The tissue damage was irregular or uneven

‘jumping’or‘mosaic’inappearance.In addition

the differences of the morphological characteristics between thewound tracks due to bullets and those due to square fragments were pointed outand their causes discussed.