I am making a 6th order low pass filter.I am using this with help of http://pdf.datasheetcatalog.com/datasheet/nationalsemiconductor/DS009294.PDF
I connected this circuit as show in Proteus but is not working.May anyone tell me what wrong with this circuit diagram.
I kept cut-off frequency 318.00 Hz using R1 and C3.

 

What's wrong is you didn't read the data sheet.
As shown here
the output cannot drive a low impedance speaker.
You need to add an audio amp between the LMF60 output and the speaker.

 

I respect your reply..I did as you said..Please see my Proteus photo..but it is not working..changing R2 for more values ..not working .now any suggestion..

 

That's not an AC audio amp, that's a single transistor DC amp.

Also that circuit won't work with a single supply since the AC signal goes negative (below ground) for each half cycle..
Look on page 12 of the data sheet to see how to use the device with one supply.

 

That's not an AC audio amp, that's a single transistor DC amp.

Also that circuit won't work with a single supply since the AC signal goes negative (below ground) for each half cycle..
Look on page 12 of the data sheet to see how to use the device with one supply.

Oh !! after working a quite hard,I find a solution on youtube for proteus Error.Thank you so much for your support.
You can drink now.