Knowledge of plasticity and anelasticity of minerals are important for the understanding the large-scale dynamics of the earth. The recent advancement of tools allows us to carry out direct measurement on some fundamental various such as stress and strain at earth related pressure-temperature conditions. I will talk about a new deformation multi-anvil high pressure device; using which the results I have obtained in investigating the plasticity of mantle minerals; and the insights from those results. I will also talk about how we use synchrotron X-ray radiation as the probing tool to study the quality factor Q of minerals at mantle conditions and the observed temperature and frequency dependence of attenuation and elastic moduli.