Biology and medicine are among the most popular and competitive majors for Chinese students studying abroad. Before applying, many students go to great lengths to showcase their interest and potential in their chosen field. Participating in high-level biology competitions is one of the most effective ways to strengthen academic credentials.

Among biology competitions, BBO (Biology Olympiad) and USABO (USA Biology Olympiad) are the two most prestigious options. They are particularly popular among students in grades 9–12 who aim to pursue majors in medicine, biology, psychology, and related fields. In previous years, both competitions were scheduled on the same day, but this year the BBO has been held earlier, leaving only the USABO in April.

So what does the USABO exam entail, how difficult is it, and how should students prepare? Let’s take a detailed look.

Who Should Participate in the USABO?

The USA Biology Olympiad (USABO) is organized by the Center for Excellence in Education (CEE) and is recognized as one of the most rigorous and influential STEM competitions in the United States. In China, it is also known as BIO-USACN.

USABO awardees are highly regarded by world-class universities, including Tsinghua University, Peking University, Harvard University, Stanford University, Columbia University, and the University of Cambridge.

Eligibility:
The official requirement is that any high school student can participate. However, due to the competition’s difficulty and selective nature, students are recommended to have:

• A solid foundation in general biology

• Prior experience in biology competitions or courses

• Strong learning ability

High school juniors (Grade 11) are particularly encouraged to participate, as the exam requires advanced knowledge, strong analytical skills, and comprehensive understanding.

Students planning to apply for majors in biology, medicine, biochemistry, or psychology, or those with a deep passion for biology, will benefit most from this competition.

2026 Registration and Exam Details

• Registration Deadline: March 24, 2026

• Exam Date: April 4, 2026, 10:30–11:20 AM (50 minutes)

• Exam Locations: School or institutional test centers

Exam Format: Individual test

Question Type and Number:
50 multiple-choice questions in 50 minutes

Awards:

1. Gold Medal – Top 10% of participants

2. Silver Medal – Top 25%

3. Bronze Medal – Top 35%

4. Regional Excellence Award – Top 20% in each region (excluding national awards)

USABO Exam Content

• Cell Biology: 20%

• Plant Anatomy and Physiology: 15%

• Animal Anatomy and Physiology: 25%

• Animal Behavior: 5%

• Genetics and Evolution: 15%

• Ecology: 15%

• Systematics: 5%

USABO Difficulty Compared to BBO

Knowledge Scope:

• Breadth: USABO = BBO

• Depth: USABO > BBO

Question Volume and Difficulty:

• Number of questions: BBO > USABO

• Difficulty: BBO < USABO

BBO: The BBO includes many questions involving graphs, image analysis, and material interpretation, often closely related to real-life scenarios. Question counts have increased over the years: 135 questions in 2022 (120 minutes), 168 questions in 2023.

USABO: 50 multiple-choice questions in 50 minutes. Although all are multiple-choice, the questions are more challenging and require strong integrated knowledge.

Scoring Insight:
Typically, achieving about 50% of total points can be sufficient to earn a Gold Medal, which is awarded to roughly the top 10% of participants. However, small mistakes can cost awards, so mastering the knowledge thoroughly is essential.