In this Paper, the possibility for efficient application of electronic networks in tourism sector is researched. The necessity is proved and the model of regional tourist information system is offered. This model will enable average and small travel companies to act on the tourist market with small expenses, but with wide business opportunities. In particular, some peculiarities of using Internet for carrying out electronic commercial transactions in tourism sector are shown, and the structure of electronic commerces cycle for such transactions is elaborated in detail. Advantages of such method of effecting transactions are defined, both in regard of tourism services providers and users; also, the change of role played by tourism services operators is established. A new strategical approach to generation of tourism product is described, this being more flexible and attractive for customer. A solution is suggested for establishment of a consultative system for tourists, this targeted at search for individual tourist trips and their booking. Development of such consultative system, related to requests for variable products subject to impact of various factors in the decision-making process, is a rather complicated simulation task. The main guidelines for expert system development are considered in order to resolve the above problem.