[中文]敬启者：

我写此信的目的是邀请我们的父母 (名字、出生日期)，于即将到来的 （月份）到 （国家）探亲，为期6个月。

我们将支付他们在 （国家）访问的一切费用：国际机票、当地交通、食宿、医疗保险和全部其他有关的花费。

希望您能在他们办理签证中给与协助。如果您有任何问题，请通过下面的地址与我联系：

此致[/中文]

[外文]To whom it may concern:

I am writing this letter to invite our parents (name and brithdays) to visit us in (country) this coming (month) for aperiod of 6 months.

It goes without saying that we will cover all expenses duringTheir visit in (country), which includes international air tickets, local transportation, accmodations, medical,insurances and all other related expenses.

Your favourable consideration regarding their visa Applications will be highly appreciated. If you have any question regarding this matter, please kindly contact me at the address above

Sincerely, [/外文]