Hi

I am international student in us. I want to know associate degree in nursing(RN) is useful to convert my F1 visa to H1.

Any area of study is useful if you can find employer in the same area who is willing to sponsor you.

No at this time. H1-B for nurses are restricted to postions that meets all the following requirements:
Must have a BS
The nurse position must require a BS in nursing.
Usually, these job positions are in the administrative area for which work experience of at least 2 years is required.
Also, most of the hospitals are reluctant to sponsor H1-B visas for foreign nurse, even if they are educated in the USA.
In my reaserch on the topic, I found that less than 20 foreign nurses (nationwide) were hired as H1-B.