Q: my iMac(2009) only has mini display, my new macbook has hdmi and Thunderbolt, no mini display, any cable can make this work?

1. You must have a Late 2009 iMac. It will not work if you have an Early 2009 or older iMac model.

see > How to identify iMac models - Apple Support

2. Then if you have a Late 2009 or 2010 iMac, you will need a Mini DisplayPort to Mini DisplayPort cable.

example > http://www.belkin.com/us/p/P-F2CD008/

3. Then you connect that cable to the MacBook's Thunderbolt port and to the iMac's Mini DisplayPort.

as outlined in > Use your iMac as a display with Target Display Mode - Apple Support

Target Display Mode 2009 & 2010 iMacs

You need a 27" model to use Target Disk Mode.

Kappy is correct and I failed to include all of the facts.

If you have a Late 2009 or 2010 iMac, then it must be a 27" model.

I was typing and posting after you were already tapped with the Green wand.

and I was still in the editing mode.

You are welcome.