E-governance is the application of information & communication technologies to transform the efficiency, effectiveness, transparency and accountability of informational & transactional exchanges with in government, between govt. & govt. agencies of National, State, Municipal & Local levels, citizen & businesses, and to empower citizens through access & use of information. Governments deal with large amount of data. To ensure that such data is put to an effective use in facilitating decision-making, a data warehouse is constructed over the historical data. It permits several types of queries requiring complex analysis on data to be addressed by decision-makers.

This Paper deals with scope and use of data warehousing & Data mining in all the dimensions of e-governance like Government to Citizen (G2C) Citizen to Government (C2G) Government to government (G2G) Government to Business ,Government to NGO (G2N).Their are many methodology used to increase the efficiency of E-governance .Three complimentary trends are Data warehousing, OLAP ,Data mining. By using these technique we find that data warehousing is very  helpful in analyzing Current & Historical data finding useful pattern & support decision strategies .OLAP is useful in solving complex queries & views , interactive online analysis of data .Using Data mining technique & algorithm, automatic discovery of pattern & other interesting trends are find out

Keywords: E-governance, OLAP ,Data warehousing, Data Mining