This ongoing pilot study aims to establish and verify cultural conventional expressions as well as cultural attitudes and behaviours survey items in the East Asian (Chinese, Japanese, and Korean) context. The participants in this study are 91 Chinese, 70 Japanese, and 70 Korean native speakers attending a college in each country. Survey questionnaire of intercultural development was developed based on the intercultural competence (IC) model. It included a 33-item self-assessment instrument with a five-point Likert scale for the cultural attitude and behaviour, as well as a 38-item aural-oral discourse completion task (DCT) on conventional expressions for the linguistic attributes section. The 71 items have been validated by Chinese native speakers through descriptive statistics and the thematic analysis of responses. The preliminary results from the data provide promising prospects that imply the verification of the 71 items in the Japanese and Korean contexts. This study contributes to the field of IC in foreign language classrooms, informing both future studies and instructional practices.