Testing strength curve of 1400~1900 density grade and LC15~LC50 strength grade lightweight aggregate concrete by rebound method was studied systematically. Results show that, adopting the Chinese national unified testing strength curve, specified by JGJ/T 23-2001 of Technical Specification for Detection of Concrete Compressive Strength by Rebound Method, to detect the lightweight aggregate concrete strength, the strength scaled value obtained is higher, which would reduce the structure assurance coefficient. The special testing strength curve of 1400~1900 density grade and LC15~LC50 strength grade lightweight aggregate concrete were built, and the computed mean relative error and relative standard error are less than 12.0% and 14.0% respectively, meet the error requirement of special curve that specified by JGJ/T 23-2001 of Technical Specification for Detection of Concrete Compressive Strength by Rebound Method.