All company A's IT budget is from company B (The one that pays me now).  Company B is the 母公司.

oh....so you work under main office IT dept?

Yes.

then is company's A IT manager gives you face to look????

I see.  So company A get funds from A to hire their own IT guys, but also get human resources like you from A, so your supervisor is from A?

Mickey, nope.  My supervisor is from B.  Because I hire by company B.  IT director (company B) also is the IT director for company A.

so my boss (IT director) takes care both company's IT matters and funding/budget.

then why did you no longer work in Company A and why Company B will hire you back?

Company A lay me off before (because of they lost some big clients before)...you know cut budget ma.  The reason that Company B hire me back....not sure ar.  Maybe they know I worked in company A before, and i knew all people, system and etc.  If they put me there....easy to handle everything.  

haha sorry I had typo, let me correct them and shd get it right this time: " So company A get funds from B to hire their own IT guys, but also get human resources like you from B (for free, from A's perspective), and your supervisor is from B"