Buddhist practice involves morality, concentration, and wisdom. The ultimate goal is to abandon suffering and obtain happiness through the realization of dhammas in our everyday life. Awareness of breathing (ānāpānasati) is one of the most important ways of practicing samatha and vipassanā. During the Buddha’s lifetime, many of his disciples practiced this daily, and the Buddha himself frequently also abode in ānāpānasati. It is also practiced by many Buddhists today. Ānāpānasati takes the breath as object, starting with samatha and moving to vipassanā in a process comprised of sixteen steps. In both early Pali and Chinese Buddhist texts, there are clusters of texts centered on the theme of ānāpānasati. In the Pali canon, there are twenty suttas in the Ānāpāna-saṃyutta (SN), while texts 801–805 in the Saṃyuktāgama (Za ahan jing 雜阿含經) comprise the Chinese cluster. These two clusters, taken together, will be regarded as a single ‘Ānāpānasati collection’ for the purposes of this paper. Although both clusters are from Saṃyutta/Saṃyukta divisions, there seem to be significant differences between them. This paper returns to the early Pali and Chinese texts in an attempt to gain a deeper understanding of ānāpānasati, looking especially at the similarities and differences in the two collections.