Several nanometer luminescent samples——crystal and amorphous——were prepared by sol-gel method. Their structure and optical spectra were measured. Extended X-ray absorption fine structure was used to determine the local environment of luminescent centres of Eu

3+

in amorphous nanometer material Y

2

O

3

SiO

2

. It was shown that having the same average coordination number 6.4 and interatomic distances

the local structure of Eu

3+

in amorphows nanometer Y

2

O

3

-SiO

2

was similar to that of Eu

3+

in

X

2

type crystal Y

2

-SiO

5

. According to the structure parameter of

X

2

type Y

2

SiO

5

the crystal field parameter and intensity parameter were calculated using M. F. Reid's model with

q

L

=-0.3

α

L

=0.2(A

3

)

and so the theoretical spectra of Eu

3+

in Y

2

SiO

5

were obtainted. Once the broadening for amorphous was considered

the calculated spectra agreed with the experimental results.