Frequency-stabilized and frequency-doubled ring Nd:YAP lasers with a 6-mirror cavity or a 4-mirror cavity have been demonstrated.The designed lasers satisfy conditions both of thermal insensitivity and of optimum frequency-doubling. The secondharmonic outpllt POwers up to 800 mW and 580 mW with the intensity fluctuations less than ±2. 5% and±2% as well as the long-term frequency stabilities better than±1.9 MHz and±1 MHz have been obtained respectively for the 6-mirror cavity with an input electric power of 1.2 kW.