Abstract: Numerous experiences shows that the distribution of loose circle of deep roadway has a major impact on support design.It is necessary to master the scope of the roadway surrounding loose and determine unstable region of roadway for determining roof safety thickness and support pattern of roadway under fillings，when isolated pillars are stoped in a mine in East China.By studying the loose circle theory and its influencing factors，a reasonable rational loose circle test program is put up.The velocity curves along the hole depth direction(V_P-L curve) and the sectional view of the roadway loose area are obtained by field tests of isolated pillar mine roadway loose circle with RSM-SY5 acoustic instrument and analysis on the test results.According to the theory of loose circle support and the field tests，some research and analysis on isolation pillar roadway stability are carried out and one support recommendation is put forward.As a means of monitoring the internal deformation of the rock，loose circle test can fully reflect the real destruction and trend of mine roadway with the stoping process in mine workings，which provides scientific guidance to evaluate the stability of roadway and support the roadway in deformation.

Key words: Isolation pillar, Roadway surrounding rock, Loose circle, Acoustic test, Roadway support