The quantum-chemical study of the possibility of photobreak of С-С and С-H bonds in heptane is carried out. It is shown that the electronic excitation to the S1 state results in the strongest decrease of the two central C-C bonds and C-H bonds connected with them. Photodissociative states are found. The potential curves of excited states are obtained. It is established that the photobreak of the C-C and C-H bonds is possible through direct dissociation in a singlet electronic excited state.