Abstract: Urolithiasis is common and frequently-occurring diseases of urology.The treatment of lithiasis is not only relevant with the size,location,brittle and infection of calculi,but also affected by urolithiasis constituents.Knowing the urolithiasis constituents in advance is no doubt to guide treatment.But so far an reliable inspection method was not found to analyze accurately urolithiasis constituents in vivo.CT judge precisely the size,location of calculi and analyze roughly the urolithiasis constituents in vivo,especially the appear of dual soure CT,which provide a new method for studying urolithiasis constituents.It may be helpful to find the cause,prevention and therapy of calculi.