This study was designed to be investigated the existing of QUS parameters of the calcaneus in the immobile Japanese elderly aged 75 and over( Patients G:N hospital). The subjects were 10 men aged76-97 (mean age 82.12±6.24) and 24 wemen aged75-99(88.76±6.70). They were all ranked level in Ⅳ - Ⅴ on Care need grades and immbobiled periods were 3.88±2.79 years in men and 2.76±2.39 years in wemen.In this case,only women’s deta was used to compare with the normal samed aged women in this study Higashimurayama City (EHMC,n=72,61-89years).In body size,body weight was shown low level (under 12kg than EHMC).BMI score were 17.78±2.79 in Patient G and 23.12±3.42 in EHMC G.Al in Blood was 3.51±0.34g/d(l normalrange;3.8-5.3g/dl).In QUS parameters,Stiff ness were 35.67±13.81(in Patients)and 61.43 ±11.32 (in EHMC),BUA were 66.08±10.84dB/Mhz(in P) and 91.10±11.21 dB/Mhz.These parameters showed signifi cantly decreased than EMHC Group.These decrememts were due to decrease of mechanical stress with prolonged immobilized states