The apical-basal cell polarity endows epithelial tissues with distinct biochemical and mechanical properties at the apical, basal, and lateral sides of tissues. Mounting evidence shows that remodelling of epithelial cell polarity, where polarity regulators redistribute their locations on the cell membrane, causes changes of cell shapes that drives tissue morphogenesis during embryonic development. However, the principles underlying epithelial tissue morphology formation regulated by remodelling of intracellular polarity remain elusive. Using mathematical modelling and computer simulations, we first show how epithelial cell polarity is established, maintained, and remodelled by the interactions among the polarity regulators in the model system of fruit fly (Drosophila melanogaster). Then, based on a geometrical modelling for epithelial tissue deformation in three dimensions, we further demonstrate how tissue morphology is determined by its constituent cell mechanics. Finally, taking into account the polarity-dependent cell mechanics, we show that the feedback between cellular mechanics and polarity can lead to a self-organizing tissue morphogenesis in the absence of sustained external stimuli.