Two types of nasal place assimilation (NPA) have been proved to take place in Mandarin Chinese (MC) disyllabic words: categorical NPA and gradient NPA. The former mainly happens in /n.C/ clusters and the latter /ŋ.C/ clusters. Previous studies show that in fast speech, the nasal coda may be completely lost, indicating a possible effect of speech rate on NPA patterns. Previous studies on NPA in other languages show that not only does the consonant have anticipatory effect on the preceding nasal, but the nasal also has carryover effect on the following consonant. However, no agreement has been reached concerning speech-rate effect on NPA patterns. This study aims to examine whether the nasal coda in MC N.C clusters has carryover effect on C and how speech rate affects N.C coarticulatory patterns. A production experiment was carried out and results show that (i) coda /n/ does not have carryover effect on Cs, but the fronted /a/ does; (ii) coda /ŋ/ does have carryover effect on the consonantal onset; (iii) speech rate does not have significant effect on the overall N.C coarticulatory patterns, but does for certain Cs. The results were explained in light of the degree of articulatory constraint (DAC) model.