The samples of InGaN/GaN multiple quantum wells (MQWs) have been grown on (0001) sapphire substrate with n-GaN buffer layer by metal-organic chemical vapor deposition (MOCVD). According to the results of Rutherford backscattering (RBS)/channeling along 〈0001〉 axis, the conventional θ—2θ scans normal to GaN (0004) and (1014) plane at 0° and 180° azimuth angles and the photoluminescence (PL) properties at room temperature, we concluded that In atoms in the InGaN/GaN MQWs are highly substituted, with the substitution rate over 99%, and the average crystal lattice constants of InGaN/GaN MQWs were calculated accurately (aepi=0.3195nm，cepi=0.5198nm), which are almost equal to theoretical data. Using HRXRD and RBS,the atomic content of In was determined to be respectively 0.023 and 0.026, the result was consistent with actual growth conditions of InGaN/GaN MQWs. However,there was a great difference compared with In chemical composition obtained by PL properties, which shows that PL properties are not suitable for measuring the In chemical composition in InGaN/GaN MQWs.