Interpersonal teacher behaviour refers to the teacher-student interactions in the classroom. One way to measure these interactions is through the Questionnaire on Teacher Interaction (QTI), which is based on the Model for Interpersonal Teacher Behaviour (MITB). This study examined the structure of the Chinese version of the QTI (C-QTI) among a convenience sample of 612 secondary-school students in Hong Kong, using Smallest Space Analysis (SSA) to cross-validate a previous study of primary students utilizing the same approach. Results indicated that the C-QTI fits the MITB circumplex structure in terms of the scale order in a circular structure. The SSA map yielded six sectors: leadership-understanding, helpful/friendly, student responsibility/freedom, uncertain, dissatisfied-admonishing and strict. The two merged sectors demonstrate students' inability to distinguish between their distinct behaviours. Eight items appeared in a sector different from their original MITB location, which could be attributed to the meanings attached to the different behaviours in the Chinese cultural context of Hong Kong or to the items' lack of clarity. Comparison of secondary and primary students indicated similarities in scale and item location. However, secondary students were better able to distinguish between the different behaviours, reflecting the possible effect of their developmental level. The study highlights the need to construct contextually-relevant items and examine their existence and clarity as reflected by students' perceptions. It also suggests the utility of SSA as a useful approach to study interpersonal teacher behaviour and facilitate the QTI adaptation process.