SMD Capacitors

Test them with a capacitance meter if there is no label on the bag. If the capacitors are already in circuit then you should either remove them to test with the meter or perform an analysis of the circuit to get a transfer function and then measure the circuit response.

as red fred says

http://www.google.co.uk/search?q=smd+capacitors+codes&sourceid=ie7&rls=com.microsoft:en-gb:IE-SearchBox&ie=&oe=&rlz=1I7GGLT_en&redir_esc=&ei=SJLNTIzyNtjNjAeru-jWBw

you can use a multimeter which can measure capacitance and easily measure the value of capacitance of a capacitor which has no mark on it.