Abstract: Sandy culture experiment, combined with X ray microanalysis, was used to investigate reproductive growth and seed quality of peanut as influenced by calcium supply Results indicated that low Ca supply led to abnormal shape of peanut pollen, flaccid and expensive pollen wall , smaller and sparse starch particles Higher K peak and lower Ca, S and Si peaks were found in pollen wall with low Ca supply under X ray microanalysis, thus in turn make vigor of pollen reduced Total numbers of flowers, the fertile flowers and yield increased with the increase of calcium supply The critical Ca level of influencing total number of flowers was 0.6cmol(+)/kg, while both of those influencing fertile flowers and yield were 1.2cmol(+)/kg The significant linear correlation existed between seed Ca content and Ca supply, and the germination and seedling survival of peanut seeds were influenced directly by seed Ca content, 235 mg/kg and 278mg/kg of seed Ca contents were requested for 95% of germination and seedling survival, respectively