Children acquiring Sign Languages (SL) follow a similar developmental sequence as to their hearing counterparts acquiring spoken languages. Hearing and deaf children communicate through gestural means (mainly pointing gestures) before they are able to produce their first lexical units ─ words or signs, and representational gestures (Volterra, Iverson & Castrataro, 2006). While studying the transition between gestures and words in speech-exposed children presents no major difficulties to study, this is not the case when examining the transition from gesture-to-sign in sign-exposed children. Gestures and words are produced in different modalities, whereas gestural and linguistic development in Deaf Children of Deaf Parents (DCDP) occur occurs in the same visual-gestural modality. Making the distinctionDistinguishing between representational gestures and signs thus appears to be highly challenging. Both are produced by the manual articulators and share referential and conventional properties. These formal and functional similarities lead to the previousled to the finding that signs appear earlier than words (the so-called sign advantage, Meier & Newport, 1990), due to the lack of criteria used to describe and distinguish between communicative gestures and early signs (Petitto, 1992; Volterra & Iverson, 1995). Defining and using fine-grained criteria is then therefore essential when studying SL development. The global issue of the present study is to explore the gestural and linguistic development in French Sign Language (LSF). Our goal is twofold: 1) to collect developmental data on LSF acquisition from birth to 3 y.o. in order to consider the gesture-sign continuum along two lines: by studying the transition between prelinguistic and linguistic stages and by investigating the way children reorganize their gestural communication system during language development, i.e. how gestural linguistic components are integrated into the existing prelinguistic gestural repertoire; and, 2) to provide reliable criteria for discriminating between representational gestures and signs. Manual behaviours are identified and subsequently analysed in terms of form (according to the formal parameters of SLs: Handshape, Orientation, Location, and Movement) and function (communicative analysis according to the form’s meaning and use). We collected longitudinal data on four children exposed to LSF from birth by their deaf parents. From 3 to 21 months, Children,the children from 3 to 21 months, were videotaped at monthly intervals during 45-minutes minute spontaneous interactions. This study presents the preliminary results of one DCDP for whom 3 sessions at 10, 12, and 14 months were coded and analysed. Communicative gestures (both representational and signs) and deictic gestures were analysed in terms of frequency of occurrence. As expected, the results indicate an increase in frequency over the study period. Children In the 3 sessions, the child used more deictic gestures in the 3 sessions compared tothan representational gestures and signs. Pointing signs and gestures (representational and signs conflated) occurred significantly more often in the 14-months’ session as compared to the 10- and 12-months’ sessions. By 14 months, the analysis indicates a significant increase in frequency of signs. The results are discussed in terms of the reorganization of the prelinguistic and linguistic system.