This study investigates the conceptual meanings expressed by the Mandarin spatial prepositions or circumpositions 在…裡/zai…li/in, 在…上/zai…shang/on, and 在/zai/at via a content analysis and comparison with the English spatial prepositions in, on, and at. The data was collected from previous studies researching prepositions in both English and Mandarin. The results show that 在…裡/zai…li/in, 在…上/zai…shang/on, and 在/zai/at express some conceptual meanings as presented in their English counterparts in, on, and at. However, there are some variation between the two languages. Furthermore, native Mandarin speakers’ embodiment, e.g. UP-DOWN orientation, strongly influences their utterances expressing the concept of space. Besides, the morphological structure of a Mandarin circumposition can be varied according to different condition but native Mandarin speakers can still understand what spatial concept is expressed by the Mandarin PP when the preposition, postposition, or both are omitted. Therefore, native English and Mandarin speakers may think space differently so they may use varied prepositions to describe space. It is suggested that language learners should understand the similar and different conceptual meanings expressed by English and Mandarin spatial prepositions to avoid making mistakes when using them.