Chuanyou No.33, a double-low and high-yield CMS rapeseed hybrid ( Brassica napus L.), whose former name was ZA-9, was developed from JA8( double-low POL CMS system ) × JR8( a double-low restorer ). Chuanyou No.33 showed great hybrid superiority. The cultivar possessed the characteristics of desired agronomic quality, double-low, high yield, high oil content, early maturity, wide adaptability and acceptable resistance( tolerance ) to virus and S. sclerotiorum. In the regional tests of Sichuan, the average yield of Chuanyou No.33 was 2350.5 kg/hm2, which outyielded the control Shuza No.6 by 12.58% in 2003, with a high significance. The average yield of Chuanyou No.33 was 2314.5 kg/hm2, which outyielded the control Shuza No.6 by 9.98% in 2004, with a high significance. In the five-regional productive test , the average yield of Chuanyou No.33 was 2200.5 kg/hm2, which outyielded the control Shuza No.6 by 16.2% in 2003-2004, with a high significance . In hybrid seed F1, its erucic acid content was 0.1% in oil, glucosinolates content was 22.89 μmol/g in meal, and oil content was 40.81% in dry base. In commodity seed F2, its erucic acid content was 1.02% in oil, glucosinolates content was 27.82 μmol/g in meal, and oil content was 39% in dry base. Its resistance (tolerance) to virus and S. sclerotiorum was very stronger. The growth period of Chuanyou No.33 was 215 days, which was 1~2 days shorter than Shuza No.6, averagely. It was released by Sichuan Crop Variety Approval Committee in October 2004 and recommended to be the main popularized variety in Sichuan province.