After the Higgs discovery, lots of exotics searches have been designed to look for possible signatures beyond the Standard Model (BSM) by scanning different final state combinations. Among them, the Di-jet final states are typical signatures for new resonances with strong interactions. For heavy flavor resonance searches, the signal sensitivity can be largely enhanced by tagging the b-jet(s) in the final state. ATLAS detector is designed for both precision measurements and new physics searches. Continuous R&Ds have been performed for detector upgrades at different time scales to cope with the higher luminosities and pileups, and to retain or improve the physics object reconstruction and triggering. The Fast TracKer(FTK), a hardware upgrade of the ATLAS TDAQ system for Run 3, will be able to provide high quality tracks to ATLAS high-level trigger(HLT) after the ATLAS level-1 trigger. This will help significantly the trigger decision in HLT. The ATLAS inner tracker will be replaced for Run 4 with a whole new silicon detector (ITk). The performance studies show that a sizable improvement will be obtained for tracking with such a new detector. In this presentation, both the ongoing FTK activities and R&D work for inner tracker upgrade will be discussed, as well as their impact on b-tagging.