According to the annual, seasonal, and monthly average temperature of Vernadsky, Marambio, Esperanza, and Marsh stations from 1974 to 2013 and the seaice concentration data from the near waters, by means of the linear regression tendency estimation method and Mexican Hat wavelet analysis method, the temperature characteristics and their relationship with seaice are studied. The results show that in the recent 40 years, the temperature in the northern Antarctic Peninsula had a warming trend; the change of sea ice concentration was negatively correlated with the change of temperature. The average temperature change was 2.24 ℃ at Vernadsky, 0.88 ℃ at Marambio, 0.8 ℃ at Esperanza, and 0.12 ℃ at Marsh. Winter warming was the key to the increase of the average temperature in the northern Antarctic Peninsula. The west coast was the fastest warming region, and the high value area is on the east coast of the George Island. The temperature rising was most obvious in the middle 1990s, which was the key period of warming in the last 40 years. The seaice concentrations, except the weak growth at Marambio, were significantly reduced the remaining three stations. This change also confirms that the warming was relatively significant in West Coast and relatively moderate in the east coast and the King George Island.