Rubidium concentration of erythrocyte of healthy children aged from 6-11 years living in four areas of Sichuan Province with different selenium status was measured by PIXE and the results show that the Rb concentration in erythrocyte for the Keshan Disease area is two times more than other three areas Meanwhile the glutathione peroxidase （GSHPx） activity of erythrocyte was determined and the results confirm that children in the Keshan Disease area are really with selenium deficiency The Rb contents in rice and soil samples from the Keshan Disease area and the Se-deficiency area but with Se-supplementation to the inhabitants

were tested by INAA It was found that Rb contents in rice and soil from the former area were much higher than those from the latter This result indicates that Rb in erythrocyte of children is mainly taken from staple food （rice） and that a higher Rb level in soil is probably another environmental factor causing the Keshan Disease