Abstract: By adopting the gratitude questionnaire(GQ-6) , positive affection and negative affection scale(PANAS) , satisfaction of life scale(SLS), anti-frustration ability scale and social support rate scale(SSRS), 367 left-behind middle school students were subjected to a survey in an attempt to find out about their life satisfaction level, and the mediation role of social support and affection between gratitude and life satisfaction. Results showed that: (1) Significantly positive correlations existed
between left-behind middle school students’ life satisfaction and gratitude, social support, and positive affection, with the ex- ception of negative affection; (2) Structure equation modeling analysis showed that social support and positive affection played a completely intermediary role between gratitude and life satisfaction, through three paths: gratitude- social support- life sat- isfaction, gratitude- positive affection- life satisfaction, gratitude- social support- positive affection- life satisfaction. It is concluded that gratitude influenced life satisfaction of left-behind middle school students through its impact upon social support and positive affection.