This paper firstly reviewed development process of UPOV Conventions and briefly introduced current situation of protection of new tropical crop varieties in China. Using SWOT approach, it analyzed internal strengths, weaknesses, external opportunities and threats of breeding R&D of tropical crops if implementing UPOV Convention 1991 Act in China. Internal strengths include rich resources, strategic significance of tropical crops, solid crop breeding foundation, and broad market prospect. Internal weaknesses include insufficient reserve of germplasm resources, weak R&D and protection of new varieties, low market level of breeding R&D entities, unreasonable structure, low input in breeding R&D, and weak protection awareness. Opportunities include bringing into play strengths of rich tropical plant resources, stimulating enthusiasm for new variety R&D and awareness for variety protection, promoting structural optimization of breeding input entities, raising technology level of breeding R&D, and promoting international cooperation of new variety protection. Threats include more strict restriction of intellectual property right, impact to weak fields of new variety R&D, and difficulty in implementing limitation of farmer privileges. Finally, it came up with four recommendations for breeding R&D of tropical crops in China in the contest of implementing UPOV Convention 1991 Act.