Abstract:The tubulin in mung bean (Phaseolus radiatus L.) seedling was purified by employing DE-AE-A50 ionic exchange column and PGGE. Western blot and immunodot analysis indicated that there are two kinds of isotubulins which have different degree of polymerization. The subunit molecular weights of monomer were 56kD and 56.5kD and those of tetramer were 54 kD and 54.5kD. The results suggest that the assembly of α-and β-Subunit is a selective process which might be related to the expression of tubulin genes.