Abstract: In order to study the relationship between summer low temperature in the northeast China and El Nino, and the variation trend and influential factors of the relationship. Based on the monthly mean temperature data of 26 observational stations in the northeast China during 1951-2011, the impact factors of the summer low temperature event in the northeast China were analyzed. Results showed that: the impact factors respectively were: general atmospheric circulation, east Asian summer monsoon, El Nino, PDO and solar activity. Solar activity, El Nino and PDO were the leading impact factors. Before 1977, PDO showed cold phase, so the east pattern El Nino appeared easily. The east pattern El Nino usually led to low summer temperature in the northeast China. During 1978-2005, PDO showed warm phase, and the middle pattern El Nino took place easily, so the trend of low summer temperature event would be significantly weakened. Totally, El Nino could significantly influence the low summer temperature event in the northeast China, but there relationship was very complicated. All the impact factors influenced the low summer temperature event jointly.