To the Rig Veda belong two Srauta Sutras – Sankhayana Srauta Sutra and Asvalayana Srauta Sutra.
The Sankhayana Srauta Sutra is regarded as the work of Suyajna Sankhayana and consists of eighteen adhyayas (books or chapters). It is not very systematic nor homogeneous in composition and betrays ample indications of later interpolations. It last two books deal with the Mahavrata rite, augmenting the description as contained in the Sankhayana Aranyaka (Adhyaya I-II) and are apparently later additions. Similarly, the legend of Suna sepa (XV. 17-27), which bears no real connection with the subject matter of this book, is presented with certain additions and alterations from the version found in Aitareya Brahmana. The Sulagava, which is essentially a grihya rite, is found in this Srauta Sutra (IV 17-20) instead of Grihya Sutra. The tenor and style of the first thirteen adhyayas differs from the following three, and the last two are definitely later additions. It has largely drawn upon the Kaustaki Brahmana and betrays verbatim agreement with it in numerous passages.
Asvalayana Srauta Sutra is the work of Asvalayana, who also wrote the Grihya Sutra. It consists of two sakas (purva and uttara), i.e., two groups of six adhyayas each. It does contain a separate chapter on paribhashas but deals with them as the necessity arises. It is thus neither a very systematic nor well-arranged Srauta Sutra like others other and Asvalayana does not seem to be very particular about brevity even. It is affiliated to the Sakala Sakha of Rig Veda and the Aitareya Brahmana. Of these two Srauta Sutras of Rig Veda, the Sankhayana Srauta Sutra seems to be older on the basis of language, which seems to be similar to that of the Brahmanas.