We report the results of a search for B- → J/ ψ Λp̄ based on a data set of 78 fb-1 data collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric e - collider. No substantial signal is found, and we set the branching fraction upper limit Β(- → J/ ψ Λp̄)<4. 1× 10-5 at 90% confidence level. © 2004 The American Physical Society.