Abstract: This paper investigates the accumulation and elimination of malachite green (MG) and leucomalachite green (LMG) in Pacific white shrimp Litopenaeus vannamei. The shrimps were exposed to MG with the medicated bath (0.2 mg · L^-1) for 2 h, and then reared in tanks containing salinity (28) indoor or outdoor. The residues of MG and LMG in the head and muscle of L.vannamei were determined by LC/MS/MS. The maximum accumulation of MG and LMG in L.vannamei were found after 2-hour bath. After being reared in an MG-free tank for 168 h, the residue concentration of MG and LMG in L.vannamei were all below the limit of detection. Compared with indoor environment, outdoor environment cultivating has a faster metabolism. Among all the cultivating conditions in this research, MG and LMG in the head of L.vannamei show a faster metabolism than those in the muscle, and MG eliminates faster than LMG