The objective of the current research is to examine the semantics of sentence connectors in reading comprehension. To achieve this objective and answer the research questions both qualitative and quantitative data was collected for the research. The sample for the current research was two textbooks from Cambridge ‘O’ and ‘A’ levels. For this purpose, a corpus of 20 reading passages was developed. To investigate the sentence connectors in selected passages Halliday and Hassan model (1976) of grammatical cohesion was applied as a theoretical framework. The findings of the current research reveal that both the textbooks have utilized sentence connectors frequently, but the overall ratio of all sentence connectors’ categories is more frequent in ‘A’ levels textbooks while ‘O’ levels textbooks have utilized various temporal connectors instead. Each word-category of sentence connectors executed specific semantic function within a text to create more cohesive ties. This research may serve the purpose to bring more researchers into this field. The findings and methodology will be helpful for teachers in teaching reading comprehension
