Venice public finance at the XVIII century depended on the needs of military politics. Large deficits and quickly hoarding of public debt appeared whenever the hostilities began. Financial authorities made easier the return to the balance of public economy, whenever peace came back. Also at the beginning of XVII century public finance seems dependent on military politics, but at that time by means of storing up a war treasury. This tool became readily obsolete when the inflationary process due to the inflow of silver from America to Europe attenuated. Financial data and official documents reveal that government aimed at a size of the public economy consistent with the private one. This limited the growth of both public debt and war treasury. Up to first half of XVIII century we can recognize a mercantile mark in the political economy of the republic. After 1750, perhaps owing to military weakness, Venice seems to drop the war as tool to exert its external power.