In the same year, He was chosen by the Defense Department of Qing Dynasty to study in Japan in the 11th class of Tokyo Shimbu Gakko; a military preparatory academy.

In 1911 after the outbreak of Wuchang Uprising, He came back to China with other members of Tongmenghui to work for Chen Qimei, who was governor of Shanghai, and also known as Chiang's mentor.

During his term, he made great contributions to military service, logistics, defense construction of KMT, and his probity and cleanness won him prestige and enhanced his reputation.

He advocated no direct confrontation with the Japanese troops, and signed the Tanggu Cease-Fire Accord with General Yasuji Okamura, who was deputy chief of staff of Kantogun at that time.

After that, in an effort to prevent further conflict with Japan, He Yingqin opposed military action against the Japanese, and disarmed Feng Yuxiang's anti-Japanese army.

However, when the Blue Shirts Society (BSS), the secret organization of the Whampoa Clique of the KMT, and a firm anti-Japanese group fought back with assassination and other violent activities in 1935, the Japanese argued that it was violation of the Tanggu Truce.

With both KMT regular and BSS irregular forces out of Northern China, He Yingqin had little room for maneuver with the Japanese.

With the start of the Second Sino-Japanese War after the Marco Polo Bridge Incident in 1937, He Yingqin was appointed as chief of staff and worked with Chiang on drafting military plans.

InYunnan, he was assigned to train the Chinese Expeditionary Army, set up under the proposal of Joseph Stilwell, for assisting in Allied operations in Southeast Asia.

With the defeat of Japan in August 1945, He was appointed as representative of both the Chinese Government and the Southeast Asia Allied Forces at the September 9th ceremony in Nanjing to accept the statement of surrender submitted by General Yasuji Okamura, who was Commander of Japanese troops in China at that time, hosting the surrender of all Japanese troops in China, Burma, and India.

One year later, He was called back to be a senior military advisor, and regained the position of Defense Minister in 1948, in time to witness the collapse of KMT power.

He took the job and proposed the plan of cease-fire first and peace negotiations later, for KMT to win time for its governance in China.

The Communists exploited the cease fire to cross the Yangtze River and capture Nanjing, the capital of KMT government.

Although the KMT still had huge numbers of troops, they were poorly armed and equipped and thus no longer had the combat power to turn the tide, especially after the United States refused to supply any more military aid.

When Chiang was reelected as president of the Republic of China in 1950, He lost his election as member of the central committee of the KMT, and only gained the honorary title of senior advisor.

He took charge of several clubs and associations working for the KMT, and spent most of his time playing sports, bridge, and planting.

With the nickname of "Lucky General", he survived battles and campaigns, and lived longer than most of the patriarchs of KMT inclusive of Chiang.