In young supernova remnants (SNRs), the study of the interaction between the shock waves
and the inhomogeneous interstellar medium is a key element in understanding the SNR
evolution, cosmic-ray acceleration, and multi-wavelength emission. In particular, TeV
gamma-ray and synchrotron X-ray bright SNRs have been considered good candidates for an
efficient cosmic-ray accelerator via shock-cloud interaction (Sano et al. 2013,
2015). In the SNR RX J1713.7-3946, we performed imaging and spectral analysis of the
Suzaku X-rays and compared it with the interstellar gas distribution (Sano et al. 2010,
2013, 2015). The shock interaction with dense gas clumps enhances turbulence and
magnetic fields up to mG around the clumps, which was observed as limb-brightening of
the synchrotron X-rays and hard spectra with photon indexes of less than 2.4. Moreover,
turbulence and magnetic field amplifications may promote an additional acceleration of
cosmic-ray electrons. By contrast, the synchrotron X-rays also become bright toward
diffuse gas regions due to the high shock velocity. In this talk, we introduce recent
results and future prospects of shock-cloud interaction in the young SNRs and
interstellar gas.