  We review some of our recent progress in modelling the formation of disk
galaxies in the framework of hierarchical structure formation. Our model is not
only consistent with the local observations, but also provides a good
description of disk evolution out to redshift z~1. We use this model to
interpret recent observational results on Lyman-break galaxies (LBGs) at z~3.
Assuming that these galaxies are associated with the most massive halos and
adopting an empirical law for their star formation rates, we find that many
properties of the LBG population, including their correlations, sizes and
kinematics can be accommodated in the model.
