Luo Songtang is a kind of thick vegetable soup which originated from Ukraine. After the soup is cooked, it can be drunk hot and cold, which is very popular in eastern or central Europe. In these areas, beet is the main ingredient in Luo Songtang. Potatoes, carrots, spinach, beef pieces and cream are often cooked, so it is purplish red. In some places, tomatoes are the main ingredients and beets are the auxiliary materials. There are orange Luo Songtang and green Luo Songtang without beets and ketchup. After Luo Songtang spread to Shanghai, Shanghainese improved Luo Songtang according to their own tastes, which is a famous dish in Shanghai-style western food.

2. Luo Songtang evolved from Russian red cabbage soup. Russian red cabbage soup is hot and sour, with more acid than sweet. It was not liked by Shanghainese at first, and it was difficult to obtain materials. Therefore, Shanghainese who like to study food began to improve Russian red vegetable soup from ingredients to taste. Russian-style red cabbage soup has gradually formed a unique Luo Songtang with Shanghai characteristics, which is sweet in acid and fragrant in sweetness, fat but not greasy, fresh, smooth and refreshing.