The main objective of the project is the prediction of expected earthquake effects in important cities of Latin America, in order to reduce the possible impact of great earthquakes. This prediction have two different parts; first of all it is necessary to determine the most probable earthquake (or in some cases the bigger one) that can affect a city, i.e., seismic hazard assessment (probabilistic or deterministic) expressed in values of expected seismic effects for a particular kind of soil at a regional scale, and second, it has to be evaluated how this regional estimation varies throughout a city, that in general is placed in a sedimentary basin, where local incremental effects are commonly present. The first part is at present well known in the Latin America region, as a result of more than 20 years of seismic hazard assessment studies, probabilistic or deterministic, accomplished at national or regional scales. Their results give the initial base for our project that will not repeat this kind of work. The second part is more complicated, it falls in which it is known as seismic microzoning, a kind of work that normally involves big research teams, the use of expensive equipment and long time of registration of local earthquakes or microseisms.  An alternative to solve this problem was developed at the beginning of past decade and was successfully tested, at a global scale, in the recently finished UNESCO/IGCP Project 414 "Determination of seismic input of megacities and large urban areas". It consists of a calculation of realistic synthetic seismograms on the basis of an accurate knowledge of three dimensional structures and expected source mechanism. The big earthquake is then simulated and useful predictions about the expected ground motion can be done. During the already mentioned project 414, it has been developed or upgraded the necessary software for making the calculations. It is based on a powerful computer network in ICTP that can be remotely accessed during the project duration. As ICTP is oriented toward practical training and updating of knowledge of scientist and students from developing countries, training with this institution will be an important aspect of our program. This training will be directed to the application of advanced computational techniques to the solution of the study problem. It will be complemented with regional meetings or seminars. The objective of this project is to contribute to the seismic microzoning of the selected cities, starting with relative amplification profiles or maps based upon response spectra and elastic energy spectra computations or simple ground motion values, and with a possible final output in the form of detailed microzoning maps.  This last objective (the more desirable in microzoning studies) will depend on the quantity and quality of initial data on local structures that participants could obtain during project duration.