Thanks Zorro,
I think I start to better understand this. Here is my understanding. This circuit could be viewed as serie resonance circuit serie with paralle resonant circuit.
For serie resonant circuit, damping factor inverse with resistor. So when increasing resistant, circuit went from overdamp to underdamp.
For parallel resonant circuit, damping factor varied with resistor. So when increasing resistant, circuit went from underdamp to over damp.
When serie this together, we see first peak from the parallel resonant circuit which has higher inductance and second peak from serie resonant which has lower inductancevalue .
Rgds,