Before the nineties of the twentieth centuries the radioactive luminescence materials were used in the feeble illumination. At the beginning of the nineties of the twentieth centuries the aluminates long afterglow photoluminescence materials were invented. Soon afterwards they were used in the feeble illumination. At the nineties of the twentieth centuries the non-radioactive luminescence materials were needed in the military industries in China. CaAl

2

O

4

:Eu

2+

Nd

3+

La

3+

is an important blue long afterglow photoluminescence material. The materials are not radioactive. The preparation and the photoluminescence properties of CaAl

2

O

4

:Eu

2+

Nd

3+

La

3+

are investigated in the paper. CaAl

2

O

4

:Eu

2+

Nd

3+

La

3+

was synthesized by solid-state reaction at high temperature at a reductive atmosphere. The reductive atmosphere was the mixture of N

2

and H

2

. The reaction temperature was about 1320℃. Nd

3+

and La

3+

are the assistant activator. La

3+

was added in CaAl

2

O

4

:Eu

2+

Nd

3+

for the first time. La

3+

can prolong the visible afterglow time of CaAl

2

O

4

:Eu

2+

Nd

3+

. We detected the excitation spectrum

the emission spectrum and the visible afterglow time of CaAl

2

O

4

:Eu

2+

Nd

3+

La

3+

. The emission spectrum of the CaAl

2

O

4

:Eu

2+

Nd

3+

La

3+

sample tells that the maximal emission intensity is at =440 nm. The excitation spectrum of the CaAl

2

O

4

:Eu

2+

Nd

3+

La

3+

sample tells that the 280～380 nm lights can excite the material. The visible afterglow time of CaAl

2

O

4

:Eu

2+

Nd

3+

La

3+

is lasting more than 18 hours. The material will be used widely. Mechanism of the long afterglow photoluminescence is discussed. Electron traps play an important role in the long afterglow photoluminescence of CaAl

2

O

4

:Eu

2+

Nd

3+

La

3+

. Eu

2+

is the luminescence ion. The photoluminescence of CaAl

2

O

4

:Eu

2+

Nd

3+

La

3+

comes from the 4f

6

5d4f

7

electron transition of Eu

2+

.