I need to delete salesforce developer account.Can I do this? If yes, how?
Accounts cannot be deleted from Salesforce, just inactivated. This may seem odd, but it helps provide data consistency and it is a common practice to "inactivate" data rather than delete it.
According to the Master Subscription Agreement for developer organizations (which is what you agree to when you sign up for one),
I'm not sure what would constitute written notice, though, since the document does not specify an address for this specific purpose.
(I'm assuming you mean a developer organization, as opposed to an Account record in your org.)
(Reposted from comment as suggested.)
As @Carolyn commented to the question - I think the question is whether Developer Orgs can be deleted rather than user accounts.
The answer is the same however, developer orgs are not generally deletable.
You cannot deactivate all users in an org, and you cannot deactivate the user you are logged in as.
I would suggest:
Instead of signing up for a developer org, you can sign up for trial orgs which expire after a set period, this is better for general evaluation of Salesforce features than a developer org.