Abstract: Some small coal mines in Southwest Guizhou Province have high arsenic content，sometimes up to 3.5％ ．The application of high As-bearing coals has ca used about 3，000 people in arsenic poisoning in several villages．Coal samples from endemic arsenosis areas have been analyzed with instrument neutron activation analysis(INAA)，X-ray absorption fine structure(XAFS)，and Mossbauer spectroscopy．The modes of occurrence of arsenic and iron in high As-coals are discussed．Arsenic has different modes of occurrence in different samples ． XAFS show that arsenic mainly exists in the form of As5+．The arsenic XANES spectra．with a main peak and a shou1der，indicate the presence of at least two different arsenic forms in each sample，with the possible exception of sample J1-As6-97A．The radial structure functions (RSFs)show one major peak at about 0.125 nm，corresponding to the As -O distance in the AsO43- anion unit，and a small peak at around 0.27 nm，corresponding to As2O3．For sample J1-As6-97A，the RSF peak at 0.125 nm is more intense ，and arsenate is the dominant species of arsenic．Except for sample J1-As6-97A，the Mossbauer spectra show that 60％～91％ of iron is in the form of pyrite．For sample J1-As6-97A all iron is present as paramagnetic or superparamagnetic goethite(α-FeOOH )．The results demonstrate that arsenic exists mainly in the form of high valence，while the As203 ，arsenic pyrite and other sulfides comprise only a small fraction．Iron exists mainly in the form of pyrite(60％～91％)and jarosite (9％～40％)with one exception where all iron is present as paramagnetic or superparamegnetic goethite(α—FeOOH)．The difference between XAFs results and Mossbauer spectra indicates that arsenic and iron initially existed in different forms．It should be emphasized that in interpreting the results of XAFs spectroscopy other analytical results should also be considered．