Ukraine has banned Russian films, including TV dramas and documentaries, made since 1 January 2014 in what Kiev regards as "an aggressor state".
The ban follows other restrictive measures imposed by Russia and Ukraine on each other since Russia's annexation of Crimea in March 2014.
They have barred each other's main TV channels on their territory.
Ukraine has blacklisted 83 cultural figures, most of them Russian, whom it considers a national security threat.
Those on the list - barred from visiting Ukraine - mostly support Russia's annexation of Crimea and the pro-Russian insurgency in eastern Ukraine.
The list includes film directors Karen Shakhnazarov and Pavel Lungin and the actors Vasily Lanovoi, Valentin Gaft and Oleg Tabakov, Russia's Tass news agency reports.
The cultural tit-for-tat war has escalated during the conflict in eastern Ukraine, where pro-Russian separatists control much of the Donetsk and Luhansk regions.
Ukraine accuses Russia of waging a propaganda war against it, and of helping the rebels with heavy weapons and professional soldiers. Moscow denies that, but says some Russian "volunteers" are helping the rebels.
The international security organisation OSCE says there are many daily violations of the Minsk ceasefire accord by both sides.
Ambassador Martin Sajdik, an OSCE special representative, spoke of 4,700 violations in just 24 hours, including deployments of heavy weapons that should have been stored.
Russian is widely spoken in Ukraine - not just in the east - and millions of Ukrainians have ethnic Russian relatives. There was a shared culture in Soviet times, before 1991, and most Soviet-era films can still be shown in Ukraine.
Similarly, Russia has banned many Ukrainian performers. That blacklist includes many Ukrainian pop and rock stars popular in Russia, BBC Ukraine specialist Olexiy Solohubenko reports.
Last August, a Russian court jailed Ukrainian film-maker Oleg Sentsov for 20 years for plotting terrorist acts in Crimea. He pleaded not guilty.
The new ban on Russian films was signed into law by Ukrainian President Petro Poroshenko on Wednesday.
It also includes any Russian films made since 1991 that "glorify the work of [Russian] government bodies".
It widens an existing Ukrainian ban on Russian films and TV series that, in Kiev's view, positively portray Russian secret police or other security forces.
Dozens of Russian books are also on a Ukrainian blacklist, because they are perceived to contain Russian nationalist messages.
Wide-ranging tit-for-tat trade embargos are also costing both countries billions of dollars.
Ukraine has stopped exporting arms and military components to Russia and no longer buys gas from Gazprom.
Russia and Ukraine have hit each other with food import bans, including dairy produce and vegetables.