The feedback of massive stars and clusters, such as radiation, wind, and supernovae, accounts for most of the energy budget in galaxies. However, our understanding of massive stars and cluster formation, especially the early evolutionary stages is still poor. The early evolutionary phases are crucial for understanding the initial conditions of massive star and cluster formation. Massive and dense infrared dark molecular clouds (IRDCs) that show no signs of ongoing star formation activities are considered to be the cradle of the massive stars and clusters. In order to investigate the formation of massive stars and their associated cluster, we carried out a systematic program with the ALMA and other interferometers toward IRDCs. Our studies yield promising clues to the formation of massive stars and protoclusters at the extreme early evolutionary stages. In this talk, I will present a detailed of our recent study on 70 micro dark massive clumps using ALMA observations on a few 0.01 pc scales, including fragmentation, turbulence, molecular outflows, accretion, the physical and chemical properties of prestellar/protostelar core, etc.