I am curious to know if you plan to stay and marry work business in thailand is it possible to get dual citizenship keep your own natioanility and become thai as well

Although it is possible, it takes a very long time. Very few people actually obtain citizenship.

You first step is to get proper employment, stay on 3 consecutive 1 year extensions (they can be based on your marriage or your employment, marriage being better as it will not be interrupted by changing jobs). If you break consecutive 3 years, the count starts again!

Paying taxes during the whole 3 year, after that you can apply for residence. When you gained that you do not have to worry about visa's anymore. But by now you'll be living some 5 years in Thailand!

Applying for citizenship comes after this!

the OP's actual question has not been answered

Sorry, so in case we fast forward 7 to 10 years and the OP finally get's his Thai citizenship, it will depend on his original nationality whether they allow dual citizenship or not.

For example Japan, India, Denmark and Singapore do not allow dual citizenship!

At the moment it is not a problem for Thailand, you do not have to renounce your current nationality when getting your Thai citizenship, but again, who knows what will be the situation that many years in the future.

The question cannot be answered, as there is not enough information. Technically he can get Thai citizenship, although the process is very lengthy. Thai law doesn't have any problem with dual nationality.

Another question is if your own county will allow dual nationality. Many countries allow dual nationality in case of getting it by way of law (mother or father having that nationality) but not if you opt (volunteer) to get another nationality. There are countries which make exceptions, such as in the case when you take on the nationality of your spouse.

Thanks, informative, clear and brief.

Thai law is rather ambiguous on the issue of dual citizenship. It neither explicitly prohibits nor condones it. The closest it comes to being specific is two clauses in The Nationality Act that say that naturalised Thais can have their citizenship revoked if: 1) there is evidence that they still make use of their former nationality; and 2) they reside outside Thailand for more than 5 years. To my knowledge there are no ministerial regulations or guidelines that clarify exactly what these clauses mean or how they should be implemented. Neither have I heard of any cases where these clauses have ever been used. What is clear is that there is no way to revoke citizenship of Thais who are Thai by descent from a Thai parent or parents, whereas naturalized Thais can also be cast out for "behaviour contrary to public morals", even if they don't have another nationality, and this has been invoked in recent years in the case of a Burmese drug dealer. Heightening the ambiguity is a new ministerial guideline for applicants for Thai nationality that requires a declaration made at the applicant's embassy attesting that he or she will renounce their original nationality, if they are approved for Thai nationality. It is not quite clear what this means and even the Special Branch officers that handle nationality applications are confused by the guideline. See more detailed discussion here http://www.thaivisa.com/forum/Story-Thai-C...html&st=300