This study aims to examine the light weight impact sound insulation of dry type system in apartment house. To achieve this goal, sounds which have same loudness according to rating methods were suggested to subjects. And followings are results. 1) The measurement frequency level average of dry type system-on is more suitable than that of dry type system-off which are dependent on specific frequency for light-weight floor impact sound. 2) Level average for measurement frequency of 100∼ｾ500Hz is more correspondent to vibration-acoustic response than that of measurement frequency of 100∼!500Hz which is for KS F 2863-2, existing rating method.