Abstract:Asparagus officinalis calli were induced from shoot of seedlings. After mutagenization, two lysine plus threonine resistant mutant lines (LTR2, LTR3) were obtained by selectionnonselection-reselection procedures with 2 mmol/1 lysine plus threonine. LTR2 and LTR3 caIli remained resistance to lysine plus threonine after being subcultured for 1 year, and both of them showed cross resistance to 1 mmol/l aminoethylcysteine. In resistant calli, the free lysine, methionine and an unknown amino acid were l-l0 times more than those in controls.