Referring　Seasonal　Energy　Efficiency　Ratio(　SEER)　-　a　method　for　seasonal　performance　evaluation　of　room　air　conditioners　in　GB　7725,　the　Seasonal　Temperature　Effectiveness　was　proposed　to　evaluate　thermal　seasonal　performance　of　a　heat　pipe　heat　recovery　unit　based　on　the　annual　operation　data　in　a　shopping　mall.　And　its　calculation　formula　was　deduced　thereafter.　With　the　case　study,　it　was　indicated　that　seasonal　temperature　effectiveness　of　the　unit　was　66.08%　in　the　winter　and　55.43%　in　the　summer,　which　meant　that　the　system　was　efficient.