Eu

3+

-doped oxyphosphate (La

3

PO

7

) nanoparticles were synthesized by a straightforward combustion method. The synthesis procedure is similar to that of preparing oxide nanomaterials by the combustion method

but here (NH

4

)

2

HPO

4

is used in producing phosphate nanoparticles. Firstly

La(NO

3

)

3

was prepared by putting appropriate molar rate La

2

O

3

(1.5mmol) and Eu

2

O

3

into the thin HNO

3

stirring to a transparent solution. Excess water was evaporated and made it condensed while heating to obtain the solid La(NO

3

)

3

. Then

put into 10mL thin HNO

3

. At the same time

0.1321g (NH

4

)

2

HPO

4

and 0.2703g Glycine were dissolved in deioned water (10mL). Thirdly

the solution of (NH

4

)

2

HPO

4

and glycine were added into that of the La(NO

3

)

3

with vigorous stirring. The precursor solution was formed. Then

the precursor solution was heated until the white foam was obtained. The reaction took place in a few minutes and all the reactions happened in a wide-mouth beaker. A monoclinic lattice was verified in them by the investigation of X-ray diffraction (XRD). In the emission spectra of Eu

3+

the

5

D

0

7

F

0

transition is often observed when Eu

3+

is in low site symmetry because it is forbidden based on the group theory. The

5

D

0

7

F

1

transition is parity-allowed magnetic dipole transition

which is slightly affected by the symmetry of the Eu

3+

site. The

5

D

0

7

F

2

transition is a parity forbidden electric dipole transition and strong emission only occurs in a non-inversion symmetry site. Under 254nm excitation

La

3

PO

7

:Eu

3+

nanoparticles emitted mainly red fluorescence

assigned to the

5

D

0

7

F

2

transition of Eu

3+

ions and revealed the Eu

3+

ions occupied asymmetric sites in the oxyphosphate host. After annealing at different temperatures from 400℃ to 1200℃

we found that the higher the annealing temperature

the better the samples crystallized and the bigger the intensity ratio of I(

5

D

0

-

7

F

2

)/I(

5

D

0

-

7

F

1

). In comparison with LaPO

4

:Eu

3+

an orange phosphor with stronger

5

D

0

7

F

1

emission

La

3

PO

7

:Eu

3+

has prominent red luminescence under the same excitation and maybe become a promising red phosphor for PDPs and Hg-free fluorescent lamp in the future.