Two experiments examined the effect of connectives in sentence and text reading. The arguments about the role of connectives are between delayed integration hypothesis and incremental interpretation. According to delayed integration hypothesis, readers process two clauses linked by a connective by interpreting each clause separately and combining them when they reach the end of the second clause. However, incremental interpretation considers semantic processing takes place incrementally. In the first experiment, readers’ eye movements were monitored as they read sentences containing adversative connectives “but” with different clausal semantic relatedness. The results showed readers spent more processing time on clauses with less semantic relatedness. Connectives helped reader integrating clausal semantic information. There was no interaction between clausal semantic relatedness and connectives. Moreover, readers’ first gaze duration on the end of second clause was not longer than any other content words. It seemed to indicate readers didn’t integrate clauses at the end of the second clause. Readers integrated words incrementally. In the second experiment, both adversative and causal connectives were inserted in texts. The incremental interpretation was also observed. These experiments support that connectives facilitate reading and readers integrate semantic units incrementally.