Progress in technology and theory of materials heat treatment is generally introduced. Late research on pearlitic transformation in steel revealed that there exist orientation relationships(OR) between α and γ 1 as well as Fe\-3C and γ 1 of neighbor grain but α and Fe 3C grow to the other grain γ 2. There also exists OR between α and Fe 3C and they grow by means of ledge. The branching of α or Fe 3C in a colony leads the formation of another colony. Debate on mechanism of bainite formation, i.e, it obeys shear or diffusional mechanism is still continuing. Some concepts of martensitic transformation ought to be altered, for example, the Magee's kinetics equation should be modified for low carbon steel. New results need to be utilized, such as the dimensional stability of GCr15 (AISI 52100) steel part would be improved by the formation of isothermal martensite from the retained austenite. Progress in ageing technique and research on mechanism of age hardening in Cu\|Al and developing a series of age hardening alloys is briefly presented. A new mechanism for embrittlement in tempered martensite )TME) is introduced, i.
e, the related processes of Fe 3C precipitation from martensite and from retained austensite induce TME, and short time tempering process and addition of Ni element in steel are suggested in order to avoid tempered martensite embrittlement. Based on the recognization of effect the surface condition on fatigue life of materials, surface treatment develops consequently. An ideal carbon concentration profile in deep carburized layer can be obtained by using dynamic control techique for potential of carbon in carburization process. Perpective in green heat treatment is described. In addition, the theory and modeling in materials phase transformations are worthy to be emphasized. Description of microstructure through field variables and the simulation of structural change based of phase field theory are also briefly introduced.