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The two-dimensional layered transition metal dichalcogenides provide new opportunities in future valley-based information processing and also provide an ideal platform to study excitonic effects.At the center of various device physics toward their possible electronic and optoelectronic applications is understanding the dynamical evolution of various manyparticle electronic states,especially exciton which dominates the optoelectronic response of TMDs,under the novel context of valley degree of freedom.Here,we provide a brief review of experimental advances in using helicity-resolved ultrafast spectroscopy,especially ultrafast pump-probe spectroscopy,to study the dynamical evolution of valley-related many-particle electronic states in semiconducting monolayer transitional metal dichalcogenides.