Objective To summarize different CT value and the corresponding calculus composition, then make an intial estimate to calculus composition; evaluate the curative effect of ESWL in different CT value. Method Establish screening condition and collected 290 patients who received ESWL in our hospital, examine CT plain scan before treatment and collect stone fragment determine the composition. Record the therapy method, process and result. Result Among calcium oxalate monohydrate calculus（716±191 Hu）, Calcium phosphate calculus（1197±221 Hu）, uric acid calculus（372±49 Hu）, calcium phosphate and calcium oxalate monohydrate calculus(981±283 Hu), uric acid and calcium phosphate calculus(556±299Hu).their CT values of the difference has statistical significance(P<0.05)；There was a statistically significant diference among once-teatment group, twice-teatment group and twice-teatment still useless group(F=44.679，P=0.000). Conclusion Examine CT plain scan before treatment can initial estimate the calculus composition and to direct the chose of treatment method.