Flow cytometry examination of ploidy level was made with four cabbage materials’s twenty-four microspore plantlets. The results indicated that microspore plantlets have four types: haploid, diploid, chimera of haploid with diploid, chimera of diploid with tetraploid. Natural ploidy level has wide difference. For big sample of microspore plantlets, based on the shape of pollen, the ploidy level can be distinguished roughly. The results showed that the natural doubling rate of different cabbage materials reaches 16.6%-100%.