According to the geographical features of the inland basins and the motion law by which a variety of chemical elements move along the rivers and deposit in the bottom of the basins in Xinjiang,the author made a series of investigations to find out the effects of the factors of environmental geochemistry on both endemic goiter and fluorosis in this area, and found that in the marginal fan belts as well as in the upper part of the alluvial plain with very sharp slope, thinner layer of soil and the emergence of the wells on the grounds, the elements moved intensively, where endemic goiter was highly prevalent, and that the contents of iodine and fluoride in drinking water showed negative correlations with the altitude. It was obvious that in the marginal fan belts and the upper part of alluvial plain, the level of such soluble salts as Cl-, Ca(++), Mg(++), K(+), Na(+) declined in parallel, and that in the lower alluvial plain, the contents increased. They may be a phenomenon occurring in concomitant with the moving of iodine. The fact that metallic elements such as V, Ba, Cr, K2 O, Rb, Er, Co, Ni, En, Mn, Fe, Cu, and Sr showed the relative stability in contents, but no laws of obvious eluviation, transfer and sedimentation in the soils of the different endemic regions of goiter in the upper and lower alluvial plains suggested that it was impossible that these elements could serve as the chemical factors responsible for goiter. In the lower alluvial plains, endemic goiter had concomitant with endemic fluorosis and the contents of iodine in both water and urine were higher, but did not reach to the level in the countries where goiter could be attributed to excess intake of iodine. The fact that in the circumstances of the lower uptake of I in thyroid for 24 hours and normal values of T3, T4-TSH, FT4I, endemic goiter still was slightly prevalent indicated that fluoride also was a factor responsible for goiter.