Agile Artifacts

Agile software engineering emphasis to use less number of artifacts in project.if the aforesaid principle is not followed what will be the negative impact on the project?

@ZUBAIR RAHIM, Are you referring to this line from the Agile Manifesto "Working software over Comprehensive documentation."

If not, could you please elaborate what do you mean by "if the aforesaid principle is not followed" ?

If yes, Agile does not say that you should not have documentation. It suggests as much documentation as needed, but give more importance to working software.

Agile Software Development is not necessarily about reducing the number of artifacts. It's about not treating non-software delivery artifacts as a measure of progress - you demonstrate progress by building software instead of publishing documents. It's also about minimizing the work that is done to what is truly required (which may or may not reduce the total number of artifacts), ensuring just-good-enough artifacts, and producing artifacts just-in-time.

Artifacts is a pretty ambiguous term. Every agile framework, methodology, process have their own artifacts whether definitive or implied.  So your statement is hard to really interpret.  I do think that @Steve and @Thomas have done justice in trying to understand your question. 

Agile as I understand doesn't really care about the number of artifacts as much as the continuous incremental delivery of value and elimination of waste associated to the delivery. 

if the aforesaid principle is not followed what will be the negative impact on the project?

If an artifact is necessary for the delivery and is not seen as wasteful, why wouldn't you create the artifact? If you are creating artifacts that have no benefit to the delivery of value or are seen as wasteful, the impact is negative towards the ability to continuous and consistently deliver value. 

If you could provide a bit more detail about the artifacts to which you refer it would be easier for us to provide you better answers.  Also a reference to something you have read that lead you to the question might be useful to us.