In Vietnamese, there exists a large set of sentence-final particles (SFPs), which playa highly significant role in oral speech. This paper presents a study on an effect of Vietnamese SFPs on generation of fundamental frequency (FO) contour. It aims to investigate the relationship between the functional status of this marginal class of words and the phonetic realization of tone. This production study is intended as a contribution towards the ultimate goal of synthesizing natural-sounding intonation which can be applied in high quality Vietnamese text to speech synthesis. The obtained results confirm that extensive tonal co-articulation is systematically observed between two adjacent syllables. As previously reported, progressive co-articulation is much more salient than regressive co-articulation and there is an influence of the function of particles on form of FO contour of Vietnamese tone.