There are two important factors that have impact on the social development and personality of undergraduates，emotional intelligence and gratitude．Several Studies have found that emotional intelligence and gratitude was significantly positive correlation, however, researchers have not investigated the causal relationship between the two factors so far. That is to say，is the emotional intelligence the cause of the gratitude or the gratitude the cause of the emotional intelligence? To find out the causal relationship，we need some longitudinal data．This kind of data can present the temporal form．In this research，we examined the development of undergraduates emotional intelligence and gratitude，as well as the correlation and causality between emotional intelligence and gratitude．406 undergraduates in grades 1-3 from a college twice (five months in between) were selected to fill out Emotional Intelligence Scale and Adolescent Gratitude Scale. The results indicated as follows: (1) According to the results repeated measures analysis of variance, emotional intelligence among undergraduates existed stability to some extent（F(1，404)=.765，p=.382＞.05），and gratitude manifested developmental changes（F(1，404)= 3.273，p=.071＜.1）; (2) Correlation analysis results indicated that the emotional intelligence was significantly positively related with gratitude(r=.57, r=.56, p＜.001); (3)cross-lagged regression analysis indicated that Time 1 emotional intelligence could predict Time 2 gratitude with Time 1 gratitude controlled（β=.094，p<.05）, but Time 1 gratitude could not predict Time 2 emotional intelligence with Time 1 emotional intelligence controlled（β=.052，p﹥.05）.The results of this study support the proposal that there exists not only correlation but also causal relationship between the emotional intelligence and gratitude, there is a close relationship between emotional intelligence and gratitude, the emotional intelligence is the cause of the gratitude. Causality research results suggested, in order to train and enhance the level of undergraduates' gratitude, researchers and practitioners can improve college students' emotional intelligence.