In two experiments, we investigated the correspondences between off‐line word segmentation and on‐line segmentation processing during Chinese reading. In Experiment 1, participants were asked to read sentences which contained critical four‐character strings, and then, they were required to segment the same sentences into words in a later off‐line word segmentation task. For each item, participants were split into 1‐word segmenters (who segmented four‐character strings as a single word) and 2‐word segmenters (who segmented four‐character strings as 2 two‐character words). Thus, we split participants into two groups (1‐word segmenters and 2‐word segmenters) according to their off‐line segmentation bias. The data analysis showed no reliable group effect on all the measures. In order to avoid the heterogeneity of participants and stimuli in Experiment 1, two groups of participants (1‐word segmenters and 2‐word segmenters) and three types of critical four‐character string (1‐word strings, ambiguous strings, and 2‐word strings) were identified in a norming study in Experiment 2. Participants were required to read sentences containing these critical strings. There was no reliable group effect in Experiment 2, as was the case in Experiment 1. However, in Experiment 2, participants spent less time and made fewer fixations on 1‐word strings compared to ambiguous and 2‐word strings. These results indicate that the off‐line word segmentation preferences do not necessarily reflect on‐line word segmentation processing during Chinese reading and that Chinese readers exhibit flexibility such that word, or multiple constituent, segmentation commitments are made on‐line.