Can we say " Actually, there are lots of jobs assessible in the western part of China."?

Yes, you must use available. Accessible makes no sense here.

I would rephrase it as:
Actually, there are more job opportunities in western China.

But, "accessible" can mean "easy to obtain ". See:http://www.ldoceonline.com/dictionary/accessible

Mister Micawber is right. A job is not 'easy to obtain' or 'accessible'. It is available and only the right candidates are offered the job if they qualify and make it through the recruitment process.

Accessible- is not the right adjective for this context. As suggested by MM, "available" is the correct choice.
I understand how you were confused because the literal meaning from Chinese translation is just that:"easy to obtain ".
The problem is, translated meaning often is misused by learners to the wrong context, and this is one.

Here are a few examples of "accessible":
Th

Thank you for your explanation!