Abstract：Our current understanding of galaxy and structure formation (both observations and theoretical modeling) in the early universe is mainly based on galaxies selected in the ultraviolet (UV), e.g., Lyman-break galaxies. However, it is known that such UV-selected galaxies are biased significantly against massive, dusty galaxies, and it remains unclear what is the true abundance of galaxies and cosmic star formation density in the early universe. In this talk, I will present some new perspectives on these issues, enabled by recent Herschel and ALMA observations of high-redshift galaxies, which shed lights on both galaxy and large-scale structure formation in the early universe. I will further discuss how these new discoveries challenge current galaxy formation models.