Currently European teachers have to develop inquiry based science teaching [IBST] in order to enhance pupils' learning and motivation towards scientific objects. Such teaching approaches are learning-focused, and appear more complex than content-centred methods. This paper focuses on 8 proficient science teachers who are involved both within professional networks and with part time in service teacher education about IBST. It aims to identify their conceptualisations and practices, and particularly about their way to cope with pupils' diversity.