This article explores the discursive behaviour of Chinese local officials in press conferences handling the recent 2015 crisis of Tianjin blasts. Drawing upon the previous analyses on relations of trust and discourse, and on the crucial aspects of trustworthiness, it examines how the officials struggled for trustworthiness discursively, and how their ‘doing’ trustworthiness varied in two phases of crisis communication. The analysis reveals markedly different approaches to the officials’ ‘doing’ trustworthiness in two phases. In the ‘unsatisfactory’ phase, the officials mainly constructed the aspect of expertise, with few expressions conveying integrity and none conveying care; while in the ‘well-handled’ phase, the officials constructed all three aspects. In addition, their discursive strategies of constructing expertise changed from extensively using ‘techs’ to combining ‘techs’ and vernacular language, and those of constructing integrity changed from not saying ‘what lacks evidence’ to providing information with adequate evidence. Effects of different aspects and discursive strategies on trust are also discussed.