i want to sent money to my girlfriend in thailand . is it safe to sent money through facebook ? any suggest ?

Is the buffalo sick again?
her mother/father's motorbike is broken?
She is starting a business?
One of her parents is ill?
Her "nephew/niece" is ill?
Her "brother" is ill?

Do western union or a bank transfer.
Teerak jai dee mak. Joop joop

Best way and safest is transfer to her bank account with direct deposit. It cost a little more than some means but it is the safest. . It would cost you around $35 to $40 to do that. You will need to know her full name on account, account number, name of bank and SWIFT code of the bank.

Western Union is another way that she will get it direct at any Western Union office which are all over the place. But she going to need to know information about the transfer so she receives the money.. But will cost more in which you pay and the exchange rate. Doing direct deposit you can the best bank rate and the money is there the next day.

Hope you know this person well. It is a common scam for people to sent money to some girl they meet online and never met in real life. Some girls work it with a number of guys. Don't buy the "her apartment got rob and they took everything including her money scam"."mother or buffalo is sick" or any other same. Sent it just like you would if she lived where you live and need the money.

You know you are one of 10 guys sending her money, right?
No honest Thai woman asks a man who is not her husband or a family member for money

I have a friend who used to send money to Thailand who told me the most secure way he found was via Western Union.

I had a long term relationship with an honest Thai girl that later became my wife (still is) and I did the following..... opened a bank checking account and included an ATM card. I sent the card to her USPS (some shippers will not take a card to send), and tightly controlled the amount of money in that account. I trained her to use the ATM card and had a bank "NO overdraft" stop on the account. A little cheaper and you can keep girl on budget without binging.
Do not listen to "old men's tales" about cheating Thai girls; just know your girl !

direct transfer to be bank account online or use western union......I am not trying to be nosy but most of these women do receive monthly allowance from multiple men

If you met her on the internet or bar. There is a 95% chance this is a scam. When I am in America I can wire money from my account there to my wife in the Philippines. She need a bank account. You need her routing number. You notice I said wife. Long term relation not girlfriend. She has her own bank account in her name.