The author deals with a comparison of the preliminary stage of the court proceedings as it was conducted pursuant to Bohemian and Moravian provincial law after the Reform of 1627-1628. Provincial law developed separately in both provinces until the early 17th century, each of them having their peculiarities. The Reform introduced the written and closed forms of trial into the law of both provinces. The comparison aimed to find out to what extent peculiarities of the two types of provincial law were preserved and to what extent these two types were unified by the Reform.