Thanks!

Unless you are confident in your writing ability, you should write addresses in romaji. In fact, you may find that the post office in your country actually insists that letters are addressed using Roman letters. I believe this is the case in the USA.

Back to the question, when I'm overseas I used to write the other parts all in romaji, but nowadays I write them in kanji. I'm Japanese and fluent in Japanese, btw.

The post office here (China) allowed me to write her address in kanji both on the envelope and customs form. Thanks for the suggestion Uco, I also added the city and country in English. I wasn't even thinking about it getting lost in another country.

WHILE IN Japan, again as long as the house number and generally speaking postal code is correct everything sort of gets "sorted out" correctly. The postal code contains a wealth of information that you could even write the city name's kanji wrong and as long as the postal code is correct it will get directed to the right area.

Faye,
Needless to say, if you want to send it by air, don't forget to write ''AIR MAIL'' in either English or any language China appreciates.