[Objective] This study aimed to test the characteristics of MAP65 in wheat mesophyll cells by co-sedimentation experiments. [Method] We used wheat Linyou 2018 as the experimental material. Western blotting analysis was carried out to de- tect the existing of 65 kDa MAP in the wheat mesophyll cells; spectrophotometery and SDS-PAGE were adopted to analyze the role of MAP65 in microtubules poly- merization in vitro. [Result] MAP65 indeed existed in wheat mesophyll cells. Co-sedi- mentation experiments showed that MAP65 can bind to microtubules, with the basic characteristics of the microtubule-associated proteins. Turbidimetric experiments showed that microtubule polymerization depended on the concentration of MAP65. Low concentrations of MAP65 promoted microtubule polymerization while high con- centrations of MAP65 inhibited microtubule polymerization. [Conclusion] This study laid significant basis for further research on physiological function of MAP65 protein.