Sui Dynasty Calligraphy, as a turning point in the transition of Calligraphy from the Southern and Northern Dynasties to the Calligraphy of the Early Tang Dynasty, has played a leading and directional role in the development of the Calligraphy of the Early Tang Dynasty. On the whole, the calligraphy of the Sui Dynasty gradually abandoned the sloppy tendency and boldness of the calligraphy of the North Dynasty. With the pen, I have absorbed the round and gentle features of the style of the Southern Dynasties, and formed a unique "Sui Kai" style. Although it lasted for a short time, and has few circulated works, it has a distinctive personality, and has become an important node and sample to understand the development process of the regular script style today. The most appropriate summary of the text is:. ['The regular script is the most outstanding achievement type of Sui Dynasty calligraphy.', 'The development of calligraphy in the early Tang Dynasty was directly influenced by calligraphy in the Sui Dynasty.', 'Sui Dynasty calligraphy has an important position in the history of calligraphy.', 'The mellowness and gentleness of calligraphy became a distinctive feature of calligraphy after the Sui Dynasty.']