Abstract: Study on a quick and effective method of castor DNA was suitable for the ISSR amplification experiment. Genomic DNA was extracted from castor tender leaf with improved CTAB method, improved SDS method and kit method, the purity and concentration was measured by spectrophotometer and agarose gel electrophoresis of the DNA, and takes it as the template for ISSR-PCR analysis. Result：Improved SDS method and modified CTAB method to extract the DNA concentration was low, the purity was not high, takes longer, operation is more difficult; Qiagen method to extract DNA concentration is higher, the purity was good, operation was simple and takes less, cost is higher. Three methods proposed in the ISSR DNA - PCR could amplify the stripe. Conclusion：Materials test under the condition of fewer,less preferred methods of extracting DNA kit, the fast and high success rate.