Abstract: Objective To investigate exprsssions of synucleins in colorectal cancer （CRC） tissues and their clinical significance. Methods We measured the mRNA levels of α-synuclein，β-synuclein and γ-synuclein of tumor tissues and adjacent normal tissues in 20 cases by semi-quantitative RT-PCR and their protein expressions in 51 cases by immunohistochemisty. Results The mRNA levels of α-synuclein，β-synuclein and γ-synuclein were 0.62±0.32，0.61±0.32 and 0.72±0.37 in CRC tissues，significantly higher than 0.41±0.27，0.40±0.25 and 0.45±0.25 in adjacent normal tissues （P=0.034，P=0.026，P=0.007）. The positive rate of γ-synuclein protein in CRC samples was 47.1％（24／51）, significantly higher than 23.5％（12／51）in adjacent normal tissues （P=0.022），while the expressions of α-synuclein and β-synuclein in CRC and adjacent normal tissues had no difference. In 8 patterns of α-synuclein，β-synuclein and γ-synuclein expressions，the positive rates of α-synuclein or γ-synuclein，β-synuclein or γ-synuclein，α-synuclein and γ-synuclein，and any synuclein expression were higher than those in adjacent tissues（P＜0.05）.α-synuclein and β-synuclein had no correlation with clinical features，while γ-synuclein protein expression was significantly correlated with stage and lymph node metastasis of CRC（P=0.047，P=0.048）. Compared with CRC of late stages and lymph node metastasis，the expression of any synuclein in early stages and without lymph node metastasis was much lower（P=0.030，P=0.040）. Conclusion α-synuclein，β-synuclein and γ-synuclein are highly expressed in CRC tissues.γ-synuclein protein is valuable for evaluation of CRC progression.