In a first approach, between two atoms A and B, two different types of chemical bonds can be possibly involved : (i) a strong with electronic exchange, (ii) a weak involving electrostatic or Van der Waals interactions.In both cases the interatomic distance A-B is an important parameter. Physics, Solid State Chemistry, Materials Sciences and Co-ordination Chemistry involve mainly strong bonds, on the contrary in Biosciences weak bonds play an important role(conformation of the molecules...).Two approaches can be used for evaluating the pressure effects on chemical bonds.(i) The chemical bond exists and, in such a case, pressure leads to a decrease of the average distance A-B inducing mainly electronic and steric phenomena.(ii) How high pressures can help the formation of a chemical bond between two atoms A and B and then induce the synthesis of new compounds ?Physics and Biosciences are mainly involved in the first approach with for Physics the study of the structural transformations and/or the electronic phenomena (charge transfer, disproportionation, electronic delocalization...).In the case of Biosciences the pressure effects on the weak bonds are very important either on the kinetics or the deformation of the molecules. In Solid State Chemistry and Materials Sciences, the induction of new chemical bonding is important for preparing functional materials. Co-ordination chemistry involves both approaches.Due to the fact that chemical bonding is an important factor for describing the research activity of different domains (Physics, Solid State Chemistry, Materials Science, Co-ordination Chemistry, Biosciences...), High Pressures appear as a fruitful tool either for the modification of existing systems or for the synthesis of new onesRead less <