The rural family of the St. Petersburg province of the mid-19th century is discussed in the article. The structural features, number of people, number of children, the position of widows and widowers in the households of the landowners' peasants of Tsarskoye Selo Uyezd according to the confession list of 1855 are examined. The scientific novelty of the work is that in the course of the study archival sources, first introduced into scientific circulation, were brought in. It is shown that the average size of the peasant household was 6.5 people, household with 1-2 children aged 0 to 14 years accounted for 61 % of the total number, the share of simple families was 41 %, complex families - 44 %. The results of a comparative analysis of the difference in the age of the spouses, carried out according to the materials of the 1st half of the 18th - the middle of the 19th centuries, are presented, the changes in the mating behavior of the peasants that have occurred over this period are revealed. The author conclude that it is necessary to study the peasant family of the St. Petersburg province based on materials from the second half of the 19th century, which will allow us to analyze the changes in the demographics of the rural population that have occurred under the influence of reforms, and will also expand the possibilities of studying the situation in this region several decades before them.