Abstract: The new mind-early ripening muskmelon cultivar‘Mingzhu 4’is the F1 offspring from the crossing between the maternal line M88-1 and the paternal line M24-2. The fruit is oval shape with white and smooth skin. The average single fruit weight is 1.5 kg. The flesh is white with a thickness of 3.5 cm. The flesh is delicate，crisp and juicy，with a clear fragrance，and the central soluble solids content is more than 16%. The whole growth period of the spring cultivation season is about 100 d and that of the summer-autumn cultivation season is about 75 d. The fruit development period is 35–40 d. The plant of‘Mingzhu 4’shows moderate growth rate and good resistance to low temperature and weak light. Meanwhile，it is comprehensively resistant to diseases，and it is easy to set fruit. The average yield of‘Mingzhu 4’is 36 750 kg • hm-2. It is suitable for planting in protected cultivation，also suitable for open field cultivation in northern China regions.

Key words: melon, protected cultivation, cultivar