This paper is devoted to a comparison of the Pratyāhārasūtra (psū) section of the Cāndravyākaraña with that of the Kāśikāvṛtti. The present study is justified in so far as the Kāśikāvṛtti shows numerous similarities with the commentary on this grammar (the Cāndravṛtti), even if the Kāśikāvṛtti does not make reference to it explicitly. The study of the psū section of the Cāndravyākaraña with its vṛtti, compared to that of the Kāśikāvṛtti, confirms the existence of numerous similarities between the two texts; very few elements of the Cāndravṛtti are not found in the Kāśikāvṛtti. In order to grasp somewhat better the peculiarities of this parallelism, I have examined the divergences shown by the two texts: for what reasons do they differ in some passages? As I try to show in this paper, some divergences can be explained very simply. It is more difficult to justify some other divergences, like the presence or the absence of sequences or of sentences. The third part of this paper is essentially devoted to this kind of problems.