This paper compares the translations of Maha Prajna-paramita Sutra, Illuminating Prajna-paramita Sutra and Light Ode Prajna-paramita Sutra with that of Da zhidu lun and from that deduces the environment in which Da zhidu lun was formed. It was the documentation of the evidence used while discussing prajna wisdom during that time period. This writer believes that what is meaningful about Da zhidu lun is not whether or not it was written by Nagarjuna but rather the place it had in the development of Chinese Buddhism. It corrects many of the misconceptions about prajna wisdom and therefore became the solid foundation on which Mahayana Buddhism developed in China.