XQuery is a powerful query language to query XML documents. Un- fortunately, its richness of functionalities makes its complex to evaluate. In [2], Chen et al. proposed to rewrite XQuery expressions in "canonical XQuery". However, their solution is restricted to a rather limited sub- set of XQuery and does not support complex XQuery expressions. We propose in this paper to extend the work of [2] to canonize the whole untyped-XQuery language.