Abstract: Leaving behind the solutions to modernist architecture alienation from the form level， which is adopted by the postmodern ideology of architecture， this study turns to a spatial approach. It holds that traditional architecture theory is different from modernist architecture theory in that the latter inherits the thought of scientific rational space. All the related elements are subjugated to this thought， which serves as the core of architectural theoretical principles. Led by this thought， the intended function is transformed into the objective quantified target， the methodological construction into the mechanical empirical approach and the resultant form into the mathematical geometric representation. In essence， modernist architecture is rational space， understanding of which will enable us to be relieved of contradictions and dilemmas and finally “dwell poetically”.

Key words: modernist architecture, construction principle, traditional space, science space