The whole area has a population of 4.9 million as of 2007.
Mandarin and local dialect are in use in the diocesan territory.
Kaifeng became the Apostolic Vicariate of Eastern Honan in 1916, covering the eastern and southern parts of the province. Italian Archbishop Noè Giuseppe Tacconi was the first apostolic vicar.
After taking office at Kaifeng, Archbishop Tacconi visited the United States and some European countries three times raising fund to build the cathedral. Buying a piece of land where the cathedral now stands, the archbishop got the help from a French company to start the construction in 1917. The church completed the building in 1919. The church compound is composed of the main church, a bell tower, archbishop's office, a minor seminary, a parish office, reception, staff quarter and a car park. The main church has an area of 625 square meters and can accommodate 1,000 parishioners. The compound was at that time one of the biggest and best projects. It is also the best maintained church architecture in Henan.
In 1924, the apostolic vicariate was renamed into Apostolic Vicariate of Kaifengfu. In 1927 and 1928, it lost territories to establish the Apostolic Prefecture of Xinyangzhou and Guide respectively. In 1946, it was erected as the Diocese of Kaifeng.
Kaifeng is located at the center of the country. Rails and highways connect the coastal east and the inland west, also the national capital of Beijing at the north and the Guangdong province in the south.
The area has a continental monsoonal climate with distinctive seasons. The average temperature is 14 degrees Celsius and the annual precipitation is 670mm. The percentage of forest coverage of the area is higher than the national average.
Kaifeng is located at the central part of Henan province, with the provincial capital of Zhengzhou at its west. It is also where the alluvial plain of the Yellow River lies. The area is around 70 meters above sea level.
Kaifeng was one of the eight ancient cities in China and is called the "Center of Seven Dynasties." The State Council declared the city a national historic city.
Since the early Sung Dynasty, Kaifeng has been the center of politics, economy and culture. It was also at the time one of the most prosperous cities in the world. Pavilions, pagodas, temples and other forms of architectures of various dynasties are found in the city.
Kaifeng is home for the four popular calligraphy masters. Yu opera was also originated from the area.