Abstract: With a pseudopolyploidy of Toxicodendron vernicifluum in Zhaotong, Yunnan province as the experimental materials, and the diploid Tvernicifluum as the control group, ploidy were determined by observation of the stomotal characteristic of leaf lower epidermis, analysis of flow cytometry and measurement of genome size. The results showed that the stomata density of pseudopolyploidy of Tvernicifluum was 052 times, the length of stomata was 138 times, and the number of chloroplast in the guard cells was 173 times compared with diploid Tvernicifluum, respectively. According to the results by flow cytometry analysis, the ploidy of somatic cell in pseudopolyploidy of Tvernicifluum was 15 times to that of the diploid Tvernicifluum, the average genome sizes (the content of 2C DNA) of pseudopolyploidy of Tvernicifluum and diploid Tvernicifluum was about (122 ± 006)pg and (096 ± 004)pg, respectively, and the average genome sizes of pseudopolyploidy of Tvernicifluum was 127 times to diploid Tvernicifluum. Above all, it could be concluded that the pseudopolyploidy of Tvernicifluum was a natural triploid lacquer.