Due to rising awareness of environmental concern and regulation of the European directive EuP (Energy Using Products), eco-design requirements are becoming important issues. This thesis would like to study component-based modular product design in notebook computer. First we use the entropy weight method and VIKOR sorting method to calculate the effectiveness value of different product specifications in order to assess the effectiveness of each product. Furthermore, we develop a mathematical model for eco-design in four stages: raw materials acquisition, manufacturing, use and end of life. This model considers product composition, cost and environmental impact of various stages to find the minimal cost among different combination of components. Finally, we use a performance indicator to integrate effectiveness value and cost, in which we can find some combinations of components having not only lower environmental impact but also lower cost. These results can feedback to the design stage.