I am approaching 70 K. what is the recommended maintenance ? timing Belt change etc ? Thanks

 

At 70k, a timing belt water pump change would be due to age not mileage. Spark plugs are not due until 120k, so I would focus on the fluids (coolant, brake, and power steering). Potentially a transmission fluid drain and fill and change the fluid in the rear diff and transfer case too. If you haven't, check the air and cabin filters as well. That's all I can think of off the top of my head.

 

The most urgent would be the Timing Belt, Water Pump & related parts ( available as a kit) as 02SDGS mentioned due to age, when I purchased my 05 RX330 AWD it had 137,000 miles, the Timing Belt was not done therefore it was cracked from edge to edge everywhere.
I was fortunate it did not break on me, unfortunately it isn't something you can check visually in 5 minutes. Best to go for the replacement & piece of mind.
more about that here:
https://www.clublexus.com/forums/rx-...s-rx330-2.html
Spark Plugs could also use some attention if you find the RX running rough, difficult to start etc, if not, another 10,000 miles won't hurt but should be done then.
Transmission Fluid check that it is a reddish color on the stick with no little pieces of debris mixed in, change is recommended at 120,000 miles by Lexus, drain & fill.
Air Filter should be checked.
Transfer Case & Rear Differential should also be checked for possible leaks & need of change.

 

I was in the same boat, bought my RX330 at ~72K (now ~75K) miles and have already did a ton of maintenance.

My list:
Fluids: Oil and Transmission (Valvoline MaxLife). In the summer I will be doing: differential & transfer case, coolant, power steering, and brake.
Tires
Timing belt: Mine wasn't in too bad shape but the tensioners were noisy. Replaced most of the parts there.
Brake Pads