7 Begonia species (cultivars) were used as materials. The leaf tissue structure, chlorophyll contents and chlorophyll fluorescence parameter F_v/F_m were observed to analyze the causes of leaf variegation formation and silver spots genetic characteristics by hybridization test. The results showed: (1) there were intercellular spaces between the abaxial epidermis cells and palisade tissue cells in variegated areas of B. deliciosa, B. handelii var. prostrata, B. pseudodryadis, ‘Oeympica’ and ‘African Jungle’, while no intercellular spaces in nonvariegated areas, the abaxial epidermis cells and palisade tissue cells were linked tightly in B. masoniana var. maculata and‘Tiger’. (2) Chloroplasts in both variegated areas and nonvariegated areas were intact of 7 Begonia species (cultivars), the thylakoid membrane was rich, and the stroma lamella and grana lamella were clear. The chlorophyll a, b and total chlorophyll contents in the variegated areas were lower than the nonvariegated areas’ in B. deliciosa, B. pseudodryadis, ‘Oeympica’and ‘African Jungle’, while in B. handelii var. prostrata there were no differences. The fluorescence parameter F_v/F_m were higher in the variegated areas than that in the nonvariegated areas of 6 Begonia species (cultivars) except B. pseudodryadis. (3) B. deliciosa hybridized with other species without variegation, the ratio of plants with variegation and without variegation was nearly 3∶1, while the ratio of plants was close to 1∶1 in its selfhybrid offsprings. The research found that the variegations of B. deliciosa, B.handelii var. prostrata, B. pseudodryadis, ‘Oeympica’ and ‘African Jungle’ were belonged to structure variegation, the variegations of B. masoniana var. maculata and ‘Tiger’ were belonged to pigment variegation. The leaf with silver spots and without silver spots were a pair of characters which can be heritable, silver spots was a dominant character.