Children are the future masters of every country. Therefore, how to provide a good family, social or learning environment for many children is an issue that all countries strive to address. At the International Conference on Child Welfare held in Geneva, Switzerland in August 1925, the concept of "International Children's Day" was first proposed.
This conference gathered representatives from 54 countries who came together in Geneva, Switzerland, to hold the "International Congress for the Happiness of Children", and passed the "Geneva Declaration on the Protection of Children". In the declaration, there were lively discussions on issues such as the spiritual enjoyment that children should have, relief for poor children, avoidance of dangerous work for children, obtaining opportunities for children to earn a living, and how to raise and care for children.
After this conference, on one hand, it aimed to encourage children and make them feel happy and joyful; on the other hand, it also aimed to draw society's attention and care. As a result, governments of various countries successively established "Children's Day".
Especially during World War II, in June 1942, the German fascists killed more than 140 male citizens over the age of 16 in the Lidice village of Czechoslovakia, as well as all the infants. Women and 90 children were sent to concentration camps. The houses and buildings in the village were burned down, and a well-established village was thus destroyed by the German fascists. To commemorate the children who died in the fascist invasion war in Lidice village and around the world, to oppose the war mongers who murdered and poisoned children, and to protect children's rights, in November 1949, the International Democratic Women's Federation held its executive meeting in Moscow and officially set June 1st of each year as the holiday for children worldwide, known as International Children's Day.

In April 1951, the International Democratic Women's Federation held a meeting in Moscow, USSR, deciding that June 1st of each year would be the International Children's Day.

The resolution called for the protection of the right to survival, health, and education of children worldwide. It pointed out that all democratic groups and adults around the world should fight against the phenomenon of employing child laborers, and that the state should protect children's health and use reduced military spending to meet the funding needs of children.

Currently, many countries around the world have set June 1st as a day for children, especially in socialist countries. In European and American countries, the date of Children's Day varies, and there are often few public celebrations. Therefore, some people mistakenly believe that only socialist countries have set June 1st as Children's Day. In fact, in recent years, some organizations in the United States have also begun to consider setting Children's Day on June 1st.