This study aims to present the results of the primary analysis realized in a case study in the training of teachers. This analysis had been aim to identify the evolutions of the didactic models involved in teaching concepts of future teachers of Chemistry by the analysis of Didactic Units built during a discipline, in which was applied a methodological intervention coherent with didactic model investigative, whose theoretical framework was supported by a proposed split into three levels of transition - from starting, intermediate and desirable - featuring the development of professional knowledge by Porlán & Rivero (1998). The results show that the subjects involved in the methodological intervention had characteristics merged into their Didactics Units of the model departure and intermediaries in the beginning of discipline, incorporating features investigative over their building, what shows evolutions of the didactic models due to the intervention. Moreover, other aspects about the teaching conceptions of future teachers were perceived, enriching the discussions triggered by the study and contributing to a better understanding of the processes of evolution of conceptions of teachers in training.