Langanite (La 3 Ga 5.5 Nb 0.5 O 14 , LGN) and its isomorphs are a few piezoelectric materials which have the unique temperature compensation and piezoelectric properties. But the high Ga 2 O 3 content makes them very expensive and limits their applications. We reported a new langanite-type compound La 3 Al 5.5 Nb 0.5 O 14 (LAN) which has the advantage of no Ga 2 O 3 content. Chemically homogeneous La 3 Al 5.5 Nb 0.5 O 14 sol was synthesized using La (NO 3 ) 3 ·6H 2 O, Al (NO 3 ) 3 ·9H 2 O and niobium citrate as starting materials. Single-phased LAN powder was prepared by decomposition of a citrate polymer precursor and subsequent reactions at high temperatures. TG-DTA, XRD and FTIR were employed to investigate the transformation process of gel to LAN powder. The results showed that, after calcination at 900 °C, pure La 3 Al 5.5 Nb 0.5 O 14 polycrystalline powder with a narrow particle size distribution was obtained, which has the same structure with La 3 Ga 5.5 Nb 0.5 O 14 .