Skobeltsyn Institute of Nuclear Physics
Lomonosov Moscow State University

In this work we present the results of the High Level Trigger (HLT) computer simulation for some $B$--meson decay channels with the ATLAS detector at LHC. We examine the trigger possibility for the decays $B_{d}^{0}\rightarrow (J/\psi \rightarrow e^{+}e^{-})\,K_{S}^{0}$, $B_{d}^{0}\rightarrow \pi ^{+}\pi ^{-}$ and $B_{s}^{0}\rightarrow (D_{s}^{-}\rightarrow \phi \pi ^{-})\pi ^{+}$. We present the cuts for HLT and study the efficiency of each cuts.