The short answer is yes: your domain name can be a trademark.
Now for the long answer...
Before registering your domain name, you need to do a search to verify that you will not be infringing on someone else's trademark. Registration of a domain name, however, does not mean that you'll be able to claim trademark rights of the name.
A purely descriptive domain name is unlikely to be eligible for a trademark. The same is true for registered company names.
Conversely, if you have a registered trademark, you may have legal grounds to prevent someone else from registering it as a domain name.
For a domain name to be registered as a trademark or to claim trademark rights, it needs to comply with the same requirements as any other mark, i.e. it must be unlikely to cause confusion with another name.
So many variations can be used for descriptive domain names, such as hyphens, numbers etc. not forgetting the .com, .net, .org part, that it really needs to be unique to qualify for a trademark.
Many companies who registered their business names in one country or state, now have a presence on the world wide web, which creates more competition for available names.
The new business owner has the ideal opportunity to consolidate his business activities under one trademark.
Conducting searches for trademarks, registered company names and registered domain names may be a daunting task, but the only way to ensure that one single mark can be used for all applications.
The law offers protection for trademark owners against the registration of domain names similar or identical to their marks. Domain hijackers and cyber squatters are increasingly being curtailed by law, offering the owner of a mark protection against dilution of a mark and the right to sue for trademark infringement.
Domain registrations are administered by ICANN and disputes may be handled through their Uniform Domain-Name Dispute Resolution Policy (UDRP).