I. Introduction
As a fine-grained sentiment analysis task, emotion cause extraction (ECE) has received much attention in these years [1], [2], [3]. It aims to extract corresponding causes for emotion expressions annotated in advance. However, the framework relies on manual emotion labeling is not practical in realworld scenarios. Therefore, Xia and Ding [4] propose a new task called emotion-cause pair extraction (ECPE). The goal of ECPE is to extract all emotion clauses and corresponding cause clauses without annotated emotions. As shown in Fig. 1, c3 contains an emotion, which is caused by c2. c5 contains another emotion, which is caused by c4. Therefore, emotion-cause pairs of the document are {(c3, c2), (c5, c4)}.