The performance and functionality of soft matter are significantly influenced by environment such as temperature and mechanical deformation. To effectively control material behaviors, it is crucial to understand the dynamic pathway during the environmental change at nanoscale. Herein, the kinetic pathway of the order-order transition in block copolymer during temperature change was studied using time-resolved three-dimensional transmission electron microtomography. We also developed an in-situ shear test system suitable for transmission electron microscopy observations, which enabled us to examine the shear deformation behaviors inside rubber at nanoscale resolutions. Understanding the kinetic pathway is useful for the morphological evolution of block copolymers and for designing suitable transition pathways to obtain ordered structures for diverse nanotechnology applications. The development of the in-situ shear deformation system for transmission electron microscopy enabled us to understand the nanoscale origins of the mechanical properties of soft materials.