您可以在配置文件neo4j-wrapper.conf

You can change settings of JVM heap in configuration file neo4j-wrapper.conf

# Java Heap Size: by default the Java heap size is dynamically
# calculated based on available system resources.
# Uncomment these lines to set specific initial and maximum
# heap size in MB.
#wrapper.java.initmemory=512
#wrapper.java.maxmemory=512

http://neo4j.com/docs/stable/server-performance.html