Genetic diversity and relationship between 29 Chinese carrot landraces，40 orange varieties and 1 Turkey purple cultivar were investigated using phenotypic and SSR markers. Phenotypic result showed that diversity index of orange varieties was lower than Chinese landraces except for leaf length，root length and root diameter. Principal component analysis showed that Chinese orange landraces had similar phenotypic variation with orange varieties in the autumn，but different in the spring. 133 polymorphic loci were amplified from 38 pairs of SSR primers. The average number of polymorphic loci of Chinese carrot landraces and orange varieties were 4.2 and 2.9，respectively. PIC value of Chinese carrot landraces（0.74±0.06）was obviously higher than that of orange varieties（0.42±0.03）. All accessions were divided into 2 groups: group I including orange varieties and orange B0241，and group Ⅱ containing other landraces and purple cultivar L1.