Noun + 的 + 重要性
重要性 (zhòngyàoxìng) means "importance" or "significance." It is formed by adding the suffix 性 (nature/quality) to 重要 (important), turning the adjective into an abstract noun. This pattern is productive in Chinese: 可能 → 可能性, 必要 → 必要性.
大家都认识到了环境保护的重要性。
Dàjiā dōu rènshí dào le huánjìng bǎohù de zhòngyàoxìng.
Everyone has recognized the importance of environmental protection.
老师反复强调学习方法的重要性。
Lǎoshī fǎnfù qiángdiào xuéxí fāngfǎ de zhòngyàoxìng.
The teacher repeatedly emphasized the importance of study methods.
这件事的重要性不用我多说,你自己清楚。
Zhè jiàn shì de zhòngyàoxìng bú yòng wǒ duō shuō, nǐ zìjǐ qīngchu.
I don't need to say much about the importance of this matter; you know it yourself.