The need of a self-propelled anti-aircraft gun was felt from the very first days of the war. Improvised installation of quad gun "Maxim" 7.62-mm on chassis gave only a partial effect, since by its ballistic characteristics, they could not compete successfully with air targets, and larger caliber guns (37-mm or 45 - mm) required a completely different chassis.The Soviet army had to wait until 1943 to get a mobile and effective air defense in the form of the ZSU-37 AA tank. ZSU stands for Zenitnaya Samokhodnaya Ustanovka (Russian: Зенитная Самоходная Установка), meaning "anti-aircraft self-propelled mount". Armed with a 37mm gun, it could cover the sky with its explosive shells' deadly black clouds. Lightly armored, very fast and cheap to produce when it was finally developed, the ZSU-37 could drive with other tanks as a mobile air defense and then turn its guns against enemy infantry or light armored units, tearing them apart. However, the tests revealed that 37-mm gun had insufficient rate of fire and not eniugh ammunition. ZSU-37 had all chances to stay at the level of the prototype, but since nothing better was proposed, it was adopted as a temporary measure.
After the release of 75 vehicles in 1944-1945 the production was stopped. The reasons for this step are described above. In addition, the Soviet Air Force dominated in the air at the final stage of the fighting in Europe. ZSU-37 didn't participate in fight, but for several years after the war they participated in military parades.
The ZSU-37-2 Yenisei is a later, unrelated design based on the chassis of the experimental SU-100P self-propelled gun.