Present annual report-2000 described results on the third years’ task in the theme of “Mechanochemistry of Materials” approved by the IFPRI organization. The task covers development of novel material processes by means of mechanochemical treatment and its relation with a ball mill simulation work. The simulation work plays a significant role to elucidate mechanochemical phenomena of materials. The present report contains considerable findings on the relation of mechanochemical phenomena and information obtained from the simulation. The report composes of three parts; 1) mechanochemical treatment of EP dust, forming soluble vanadium (V) compound in water, 2) mechanochemical treatment of fluorescent powder, accelerating its structure change, and 3) dechlorination of PVC by its mechanochemical treatment with inorganic material such as CaO. Regarding the first example, the yield of vanadium extracted by water leaching is well correlated with impact energy of balls in the mill calculated from the result obtained by the Particle Element Method (PEM). As for the second example, the dry grinding the EP dust enables us to form a water soluble vanadium compound. The well correlation between the V-yield and the impact energy of balls is obtained, suggesting that the ball impact energy plays a significant role to control the formation of vanadium compound. The third one is dechlorination of polymers such as PVC (poly-vinyl chloride), PVDF (poly-vinylidene fluoride) and PTFE (poly-tetra fluoro ethane) by their mechanochemical treatment with inorganic material such as CaO. This work has been presented at the IFPRI AGM 2000 held at Scheveningen, Netherlands. The present report described only the dechlorination of PVC and its correlation with the impact energy of balls in the mill calculated from the result simulated by the PEM. All the approximately same, the impact energy of balls in a mill is a significant key to control mechanochemical effect and reaction. In such sense, the computer simulation based on the PEM regarding the ball motion during milling is a quite useful tool for determining the optimum operational parameters, mill design with scaling-up.