A　clear　description　of　the　effects　of　window-wall　ratio　and　heat　insulation　of　building　envelope　on　thermal　application　of　solar　energy　as　well　as　energy　consumption　for　heating　and　cooling　demands　in　residential　buildings　was　given　in　this　paper.　Under　different　window-wall　ratios　and　different　heat　insulation　levels　of　building　envelope,　energy　simulations　have　been　carried　out　for　a　typical　residential　building　in　Shanghai　using　DeST　software.　Results　showed　that　thermal　application　of　solar　energy　can　be　improved　with　the　greater　south　window-wall　ratio　and　the　higher　level　of　heat　insulation　of　building　envelope,　and　window　shading　and　night　ventilation　in　summer.　Due　to　these　efficient　utilizations,　energy　consumption　for　heating　and　cooling　demands　in　residential　buildings　will　be　reduced.