It is important to grasp chemical species of radiocesium and radioiodine in various samples in Fukushima to understand and predict their behaviors in environment. In particular, interaction of clay minerals and humic substances are important for the migrations of radiocesium and radioiodine, respectively. XAFS spectroscopy and micro-XRF techniques are useful to identify these species. High stability of inner-sphere complex suggested by XAFS shows that the migration of radiocesium in aquatic system is primarily determined by that of particulate matters. Incorporation of radioiodine into humic substances indicated by XAFS can explain the retention of radioiodine at the surface of soil layer.