This paper investigates pragmatic factors affecting the development of the focus particle lian in Mandarin Chinese. An analysis of lian’s evolution in historical texts demonstrates that lian’s semantic transformation from concrete activity to abstract grammatical meaning involved two major processes: metaphorization and inferencing. More importantly, this study provides evidence to show that due to the isolating characteristic, 1) Chinese does not restrict metaphorization to any particular category of lexical items, as Indo-European languages do (cf. Heine 1993); 2) different kinds of inferencing have affected lian in its process of semantic change and grammaticalization as opposed to the claim that different kinds of inferencing occur with different types of lexical items (cf. Traugott and König 1991); and 3) both divergence and desemantization are the results of lian’s grammaticalization.