A laboratory experiment was conducted to study the effects of speech intelligibility on English scientific literature reading performance in Chinese open-plan offices (both the occupants' native language and ambient speech noise were Chinese). The objective performance and subject perceptions of 20 participants were tested under different speech intelligibility conditions. The results highlight the significant negative impact of speech noise on occupants' performance. Moreover, a comparison of these results and those of previous studies implies Chinese occupants engaged in English scientific literature reading tasks are more sensitive to the changes of speech intelligibility and have higher requirements for acoustic environment.