This study has analyzed the LCA of apartment complex to quantitatively evaluate the environmental impact of materials used for material production stage in the entire cycle. This study has also presented methods to simplify environmental impact evaluation on apartment complex by selecting major materials. The research findings on the environmental impact of 27 units of apartment complex are as follows. Sales facilities of per unit area (/$m^2$), which constitutes the complex had the biggest impact of $5.41E-02pe{cdot}yr$, followed by other facilities ($5.07E-02{cdot}yr$), welfare facilities ($3.51E-02{cdot}yr$), underground parking lot ($3.37E-02{cdot}yr$), apartment buildings ($3.11E-02{cdot}yr$), and common areas ($6.05E-03{cdot}yr$). Meanwhile, major materials were selected as follows: 15 types of apartment buildings; 5 types of underground parking lots, welfare facilities, and sales facilities; 5 types of other facilities; 26 types of common areas.