The conceptions, practices and efforts of some education systems in ten countries and four continents of the world, in area of national curriculum, have been reviewed and analyzed in this inquiry to represent a brief look of their experiences and obtain some guidelines for delineating and developing national curriculum. The methodology in this inquiry has been descriptive and analytical research with emphasis on the qualitative dimension of inquiry. The selection of educational systems as inquiry sample has been purposeful. Data gathering from the countries has been done through the six components of the inquiry which are the main criteria in reviewing, assessing and delineating national curriculum practices and conceptions in these education systems. They are as below: 1- goals and other curriculum main elements; 2- conceptions and theorization; 3- necessities, preconditions and foregrounds; 4-structural and implementation characteristics; 5- attention to school based curriculum development; and 6-interest to the field of curriculum orientations.